prompt: [version 2.20.0] TypeError: 'NoneType' object is not subscriptable
  After update from version 2.19.5 to 2.20.0 I got error for code like:
  
  ```python
  from marshmallow import Schema, fields, validates
  
  
  class Bar(Schema):
      value = fields.String()
  
      @validates('value')  # <- issue here
      def validate_value(self, value):
          pass
  
  
  class Foo(Schema):
      bar = fields.Nested(Bar)
  
  
  sch = Foo()
  
  sch.validate({
      'bar': 'invalid',
  })
  ```
  
  ```
  Traceback (most recent call last):
    File "/_/bug_mschema.py", line 19, in <module>
      'bar': 'invalid',
    File "/_/env/lib/python3.7/site-packages/marshmallow/schema.py", line 628, in validate
      _, errors = self._do_load(data, many, partial=partial, postprocess=False)
    File "/_/env/lib/python3.7/site-packages/marshmallow/schema.py", line 670, in _do_load
      index_errors=self.opts.index_errors,
    File "/_/env/lib/python3.7/site-packages/marshmallow/marshalling.py", line 292, in deserialize
      index=(index if index_errors else None)
    File "/_/env/lib/python3.7/site-packages/marshmallow/marshalling.py", line 65, in call_and_store
      value = getter_func(data)
    File "/_/env/lib/python3.7/site-packages/marshmallow/marshalling.py", line 285, in <lambda>
      data
    File "/_/env/lib/python3.7/site-packages/marshmallow/fields.py", line 265, in deserialize
      output = self._deserialize(value, attr, data)
    File "/_/env/lib/python3.7/site-packages/marshmallow/fields.py", line 465, in _deserialize
      data, errors = self.schema.load(value)
    File "/_/env/lib/python3.7/site-packages/marshmallow/schema.py", line 588, in load
      result, errors = self._do_load(data, many, partial=partial, postprocess=True)
    File "/_/env/lib/python3.7/site-packages/marshmallow/schema.py", line 674, in _do_load
      self._invoke_field_validators(unmarshal, data=result, many=many)
    File "/_/env/lib/python3.7/site-packages/marshmallow/schema.py", line 894, in _invoke_field_validators
      value = data[field_obj.attribute or field_name]
  TypeError: 'NoneType' object is not subscriptable
  ```
  
instance: {"FAIL_TO_PASS": "[\"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_wrong_nested_type_with_validates_method\"]", "PASS_TO_PASS": "[\"tests/test_marshalling.py::test_missing_is_falsy\", \"tests/test_marshalling.py::TestMarshaller::test_prefix\", \"tests/test_marshalling.py::TestMarshaller::test_marshalling_generator\", \"tests/test_marshalling.py::TestMarshaller::test_default_to_missing\", \"tests/test_marshalling.py::TestMarshaller::test_serialize_fields_with_load_only_param\", \"tests/test_marshalling.py::TestMarshaller::test_missing_data_are_skipped\", \"tests/test_marshalling.py::TestMarshaller::test_serialize_with_load_only_doesnt_validate\", \"tests/test_marshalling.py::TestMarshaller::test_serialize_fields_with_dump_to_param\", \"tests/test_marshalling.py::TestMarshaller::test_serialize_fields_with_dump_to_and_prefix_params\", \"tests/test_marshalling.py::TestMarshaller::test_stores_indices_of_errors_when_many_equals_true\", \"tests/test_marshalling.py::TestMarshaller::test_doesnt_store_errors_when_index_errors_equals_false\", \"tests/test_marshalling.py::TestUnmarshaller::test_extra_data_is_ignored\", \"tests/test_marshalling.py::TestUnmarshaller::test_stores_errors\", \"tests/test_marshalling.py::TestUnmarshaller::test_stores_indices_of_errors_when_many_equals_true\", \"tests/test_marshalling.py::TestUnmarshaller::test_doesnt_store_errors_when_index_errors_equals_false\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize\", \"tests/test_marshalling.py::TestUnmarshaller::test_extra_fields\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_many\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_stores_errors\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_fields_with_attribute_param\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_fields_with_load_from_param\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_fields_with_dump_only_param\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_wrong_type_root_data\", \"tests/test_marshalling.py::TestUnmarshaller::test_deserialize_wrong_type_nested_data\"]", "base_commit": "2be2d83a1a9a6d3d9b85804f3ab545cecc409bb0", "created_at": "2019-08-13T04:36:01Z", "environment_setup_commit": "7015fc4333a2f32cd58c3465296e834acd4496ff", "hints_text": "Thanks for reporting. I was able to reproduce this on 2.20.0. This is likely a regression from https://github.com/marshmallow-code/marshmallow/pull/1323 . I don't have time to look into it now. Would appreciate a PR.", "instance_id": "marshmallow-code__marshmallow-1343", "patch": "diff --git a/src/marshmallow/schema.py b/src/marshmallow/schema.py\n--- a/src/marshmallow/schema.py\n+++ b/src/marshmallow/schema.py\n@@ -877,7 +877,7 @@ def _invoke_field_validators(self, unmarshal, data, many):\n                 for idx, item in enumerate(data):\n                     try:\n                         value = item[field_obj.attribute or field_name]\n-                    except KeyError:\n+                    except (KeyError, TypeError):\n                         pass\n                     else:\n                         validated_value = unmarshal.call_and_store(\n@@ -892,7 +892,7 @@ def _invoke_field_validators(self, unmarshal, data, many):\n             else:\n                 try:\n                     value = data[field_obj.attribute or field_name]\n-                except KeyError:\n+                except (KeyError, TypeError):\n                     pass\n                 else:\n                     validated_value = unmarshal.call_and_store(\n", "problem_statement": "[version 2.20.0] TypeError: 'NoneType' object is not subscriptable\nAfter update from version 2.19.5 to 2.20.0 I got error for code like:\r\n\r\n```python\r\nfrom marshmallow import Schema, fields, validates\r\n\r\n\r\nclass Bar(Schema):\r\n    value = fields.String()\r\n\r\n    @validates('value')  # <- issue here\r\n    def validate_value(self, value):\r\n        pass\r\n\r\n\r\nclass Foo(Schema):\r\n    bar = fields.Nested(Bar)\r\n\r\n\r\nsch = Foo()\r\n\r\nsch.validate({\r\n    'bar': 'invalid',\r\n})\r\n```\r\n\r\n```\r\nTraceback (most recent call last):\r\n  File \"/_/bug_mschema.py\", line 19, in <module>\r\n    'bar': 'invalid',\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/schema.py\", line 628, in validate\r\n    _, errors = self._do_load(data, many, partial=partial, postprocess=False)\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/schema.py\", line 670, in _do_load\r\n    index_errors=self.opts.index_errors,\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/marshalling.py\", line 292, in deserialize\r\n    index=(index if index_errors else None)\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/marshalling.py\", line 65, in call_and_store\r\n    value = getter_func(data)\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/marshalling.py\", line 285, in <lambda>\r\n    data\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/fields.py\", line 265, in deserialize\r\n    output = self._deserialize(value, attr, data)\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/fields.py\", line 465, in _deserialize\r\n    data, errors = self.schema.load(value)\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/schema.py\", line 588, in load\r\n    result, errors = self._do_load(data, many, partial=partial, postprocess=True)\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/schema.py\", line 674, in _do_load\r\n    self._invoke_field_validators(unmarshal, data=result, many=many)\r\n  File \"/_/env/lib/python3.7/site-packages/marshmallow/schema.py\", line 894, in _invoke_field_validators\r\n    value = data[field_obj.attribute or field_name]\r\nTypeError: 'NoneType' object is not subscriptable\r\n```\n", "repo": "marshmallow-code/marshmallow", "test_patch": "diff --git a/tests/test_marshalling.py b/tests/test_marshalling.py\n--- a/tests/test_marshalling.py\n+++ b/tests/test_marshalling.py\n@@ -2,7 +2,7 @@\n \n import pytest\n \n-from marshmallow import fields, Schema\n+from marshmallow import fields, Schema, validates\n from marshmallow.marshalling import Marshaller, Unmarshaller, missing\n from marshmallow.exceptions import ValidationError\n \n@@ -283,3 +283,24 @@ class TestSchema(Schema):\n \n             assert result is None\n             assert excinfo.value.messages == {'foo': {'_schema': ['Invalid input type.']}}\n+\n+    # Regression test for https://github.com/marshmallow-code/marshmallow/issues/1342\n+    def test_deserialize_wrong_nested_type_with_validates_method(self, unmarshal):\n+        class TestSchema(Schema):\n+            value = fields.String()\n+\n+            @validates('value')\n+            def validate_value(self, value):\n+                pass\n+\n+        data = {\n+            'foo': 'not what we need'\n+        }\n+        fields_dict = {\n+            'foo': fields.Nested(TestSchema, required=True)\n+        }\n+        with pytest.raises(ValidationError) as excinfo:\n+            result = unmarshal.deserialize(data, fields_dict)\n+\n+            assert result is None\n+            assert excinfo.value.messages == {'foo': {'_schema': ['Invalid input type.']}}\n", "version": "2.20"}
parsed_commit_content: {"file_diffs":[{"old_file_content":"# -*- coding: utf-8 -*-\n\"\"\"The :class:`Schema` class, including its metaclass and options (class Meta).\"\"\"\nfrom __future__ import absolute_import, unicode_literals\n\nfrom collections import defaultdict, namedtuple\nimport copy\nimport datetime as dt\nimport decimal\nimport inspect\nimport json\nimport uuid\nimport warnings\nimport functools\n\nfrom marshmallow import base, fields, utils, class_registry, marshalling\nfrom marshmallow.compat import (with_metaclass, iteritems, text_type,\n                                binary_type, Mapping, OrderedDict)\nfrom marshmallow.exceptions import ValidationError\nfrom marshmallow.orderedset import OrderedSet\nfrom marshmallow.decorators import (PRE_DUMP, POST_DUMP, PRE_LOAD, POST_LOAD,\n                                    VALIDATES, VALIDATES_SCHEMA)\nfrom marshmallow.utils import missing\nfrom marshmallow.warnings import RemovedInMarshmallow3Warning, ChangedInMarshmallow3Warning\n\n\n#: Return type of :meth:`Schema.dump` including serialized data and errors\nMarshalResult = namedtuple('MarshalResult', ['data', 'errors'])\n#: Return type of :meth:`Schema.load`, including deserialized data and errors\nUnmarshalResult = namedtuple('UnmarshalResult', ['data', 'errors'])\n\ndef _get_fields(attrs, field_class, pop=False, ordered=False):\n    \"\"\"Get fields from a class. If ordered=True, fields will sorted by creation index.\n\n    :param attrs: Mapping of class attributes\n    :param type field_class: Base field class\n    :param bool pop: Remove matching fields\n    \"\"\"\n    getter = getattr(attrs, 'pop' if pop else 'get')\n    fields = [\n        (field_name, getter(field_name))\n        for field_name, field_value in list(iteritems(attrs))\n        if utils.is_instance_or_subclass(field_value, field_class)\n    ]\n    if ordered:\n        return sorted(\n            fields,\n            key=lambda pair: pair[1]._creation_index,\n        )\n    else:\n        return fields\n\n# This function allows Schemas to inherit from non-Schema classes and ensures\n#   inheritance according to the MRO\ndef _get_fields_by_mro(klass, field_class, ordered=False):\n    \"\"\"Collect fields from a class, following its method resolution order. The\n    class itself is excluded from the search; only its parents are checked. Get\n    fields from ``_declared_fields`` if available, else use ``__dict__``.\n\n    :param type klass: Class whose fields to retrieve\n    :param type field_class: Base field class\n    \"\"\"\n    mro = inspect.getmro(klass)\n    # Loop over mro in reverse to maintain correct order of fields\n    return sum(\n        (\n            _get_fields(\n                getattr(base, '_declared_fields', base.__dict__),\n                field_class,\n                ordered=ordered\n            )\n            for base in mro[:0:-1]\n        ),\n        [],\n    )\n\n\nclass SchemaMeta(type):\n    \"\"\"Metaclass for the Schema class. Binds the declared fields to\n    a ``_declared_fields`` attribute, which is a dictionary mapping attribute\n    names to field objects. Also sets the ``opts`` class attribute, which is\n    the Schema class's ``class Meta`` options.\n    \"\"\"\n\n    def __new__(mcs, name, bases, attrs):\n        meta = attrs.get('Meta')\n        ordered = getattr(meta, 'ordered', False)\n        if not ordered:\n            # Inherit 'ordered' option\n            # Warning: We loop through bases instead of MRO because we don't\n            # yet have access to the class object\n            # (i.e. can't call super before we have fields)\n            for base_ in bases:\n                if hasattr(base_, 'Meta') and hasattr(base_.Meta, 'ordered'):\n                    ordered = base_.Meta.ordered\n                    break\n            else:\n                ordered = False\n        cls_fields = _get_fields(attrs, base.FieldABC, pop=True, ordered=ordered)\n        klass = super(SchemaMeta, mcs).__new__(mcs, name, bases, attrs)\n        inherited_fields = _get_fields_by_mro(klass, base.FieldABC, ordered=ordered)\n\n        # Use getattr rather than attrs['Meta'] so that we get inheritance for free\n        meta = getattr(klass, 'Meta')\n        # Set klass.opts in __new__ rather than __init__ so that it is accessible in\n        # get_declared_fields\n        klass.opts = klass.OPTIONS_CLASS(meta)\n        # Pass the inherited `ordered` into opts\n        klass.opts.ordered = ordered\n        # Add fields specifid in the `include` class Meta option\n        cls_fields += list(klass.opts.include.items())\n\n        dict_cls = OrderedDict if ordered else dict\n        # Assign _declared_fields on class\n        klass._declared_fields = mcs.get_declared_fields(\n            klass=klass,\n            cls_fields=cls_fields,\n            inherited_fields=inherited_fields,\n            dict_cls=dict_cls\n        )\n        return klass\n\n    @classmethod\n    def get_declared_fields(mcs, klass, cls_fields, inherited_fields, dict_cls):\n        \"\"\"Returns a dictionary of field_name => `Field` pairs declard on the class.\n        This is exposed mainly so that plugins can add additional fields, e.g. fields\n        computed from class Meta options.\n\n        :param type klass: The class object.\n        :param dict cls_fields: The fields declared on the class, including those added\n            by the ``include`` class Meta option.\n        :param dict inherited_fileds: Inherited fields.\n        :param type dict_class: Either `dict` or `OrderedDict`, depending on the whether\n            the user specified `ordered=True`.\n        \"\"\"\n        return dict_cls(inherited_fields + cls_fields)\n\n    # NOTE: self is the class object\n    def __init__(self, name, bases, attrs):\n        super(SchemaMeta, self).__init__(name, bases, attrs)\n        if name:\n            class_registry.register(name, self)\n        self._resolve_processors()\n\n    def _resolve_processors(self):\n        \"\"\"Add in the decorated processors\n\n        By doing this after constructing the class, we let standard inheritance\n        do all the hard work.\n        \"\"\"\n        mro = inspect.getmro(self)\n        self._has_processors = False\n        self.__processors__ = defaultdict(list)\n        for attr_name in dir(self):\n            # Need to look up the actual descriptor, not whatever might be\n            # bound to the class. This needs to come from the __dict__ of the\n            # declaring class.\n            for parent in mro:\n                try:\n                    attr = parent.__dict__[attr_name]\n                except KeyError:\n                    continue\n                else:\n                    break\n            else:\n                # In case we didn't find the attribute and didn't break above.\n                # We should never hit this - it's just here for completeness\n                # to exclude the possibility of attr being undefined.\n                continue\n\n            try:\n                processor_tags = attr.__marshmallow_tags__\n            except AttributeError:\n                continue\n\n            self._has_processors = bool(processor_tags)\n            for tag in processor_tags:\n                # Use name here so we can get the bound method later, in case\n                # the processor was a descriptor or something.\n                self.__processors__[tag].append(attr_name)\n\n\nclass SchemaOpts(object):\n    \"\"\"class Meta options for the :class:`Schema`. Defines defaults.\"\"\"\n\n    def __init__(self, meta):\n        self.fields = getattr(meta, 'fields', ())\n        if not isinstance(self.fields, (list, tuple)):\n            raise ValueError(\"`fields` option must be a list or tuple.\")\n        self.additional = getattr(meta, 'additional', ())\n        if not isinstance(self.additional, (list, tuple)):\n            raise ValueError(\"`additional` option must be a list or tuple.\")\n        if self.fields and self.additional:\n            raise ValueError(\"Cannot set both `fields` and `additional` options\"\n                            \" for the same Schema.\")\n        self.exclude = getattr(meta, 'exclude', ())\n        if not isinstance(self.exclude, (list, tuple)):\n            raise ValueError(\"`exclude` must be a list or tuple.\")\n        self.strict = getattr(meta, 'strict', False)\n        if hasattr(meta, 'dateformat'):\n            warnings.warn(\n                \"The dateformat option is renamed to datetimeformat in marshmallow 3.\",\n                ChangedInMarshmallow3Warning\n            )\n        self.dateformat = getattr(meta, 'dateformat', None)\n        if hasattr(meta, 'json_module'):\n            warnings.warn(\n                \"The json_module option is renamed to render_module in marshmallow 3.\",\n                ChangedInMarshmallow3Warning\n            )\n        self.json_module = getattr(meta, 'json_module', json)\n        if hasattr(meta, 'skip_missing'):\n            warnings.warn(\n                'The skip_missing option is no longer necessary. Missing inputs passed to '\n                'Schema.dump will be excluded from the serialized output by default.',\n                UserWarning\n            )\n        self.ordered = getattr(meta, 'ordered', False)\n        self.index_errors = getattr(meta, 'index_errors', True)\n        self.include = getattr(meta, 'include', {})\n        self.load_only = getattr(meta, 'load_only', ())\n        self.dump_only = getattr(meta, 'dump_only', ())\n\n\nclass BaseSchema(base.SchemaABC):\n    \"\"\"Base schema class with which to define custom schemas.\n\n    Example usage:\n\n    .. code-block:: python\n\n        import datetime as dt\n        from marshmallow import Schema, fields\n\n        class Album(object):\n            def __init__(self, title, release_date):\n                self.title = title\n                self.release_date = release_date\n\n        class AlbumSchema(Schema):\n            title = fields.Str()\n            release_date = fields.Date()\n\n        # Or, equivalently\n        class AlbumSchema2(Schema):\n            class Meta:\n                fields = (\"title\", \"release_date\")\n\n        album = Album(\"Beggars Banquet\", dt.date(1968, 12, 6))\n        schema = AlbumSchema()\n        data, errors = schema.dump(album)\n        data  # {'release_date': '1968-12-06', 'title': 'Beggars Banquet'}\n\n    :param dict extra: A dict of extra attributes to bind to the serialized result.\n    :param tuple|list only: Whitelist of fields to select when instantiating the Schema.\n        If None, all fields are used.\n        Nested fields can be represented with dot delimiters.\n    :param tuple|list exclude: Blacklist of fields to exclude when instantiating the Schema.\n        If a field appears in both `only` and `exclude`, it is not used.\n        Nested fields can be represented with dot delimiters.\n    :param str prefix: Optional prefix that will be prepended to all the\n        serialized field names.\n    :param bool strict: If `True`, raise errors if invalid data are passed in\n        instead of failing silently and storing the errors.\n    :param bool many: Should be set to `True` if ``obj`` is a collection\n        so that the object will be serialized to a list.\n    :param dict context: Optional context passed to :class:`fields.Method` and\n        :class:`fields.Function` fields.\n    :param tuple|list load_only: Fields to skip during serialization (write-only fields)\n    :param tuple|list dump_only: Fields to skip during deserialization (read-only fields)\n    :param bool|tuple partial: Whether to ignore missing fields. If its value\n        is an iterable, only missing fields listed in that iterable will be\n        ignored.\n\n    .. versionchanged:: 2.0.0\n        `__validators__`, `__preprocessors__`, and `__data_handlers__` are removed in favor of\n        `marshmallow.decorators.validates_schema`,\n        `marshmallow.decorators.pre_load` and `marshmallow.decorators.post_dump`.\n        `__accessor__` and `__error_handler__` are deprecated. Implement the\n        `handle_error` and `get_attribute` methods instead.\n        \"\"\"\n    TYPE_MAPPING = {\n        text_type: fields.String,\n        binary_type: fields.String,\n        dt.datetime: fields.DateTime,\n        float: fields.Float,\n        bool: fields.Boolean,\n        tuple: fields.Raw,\n        list: fields.Raw,\n        set: fields.Raw,\n        int: fields.Integer,\n        uuid.UUID: fields.UUID,\n        dt.time: fields.Time,\n        dt.date: fields.Date,\n        dt.timedelta: fields.TimeDelta,\n        decimal.Decimal: fields.Decimal,\n    }\n\n    OPTIONS_CLASS = SchemaOpts\n\n    #: DEPRECATED: Custom error handler function. May be `None`.\n    __error_handler__ = None\n    #: DEPRECATED: Function used to get values of an object.\n    __accessor__ = None\n\n    class Meta(object):\n        \"\"\"Options object for a Schema.\n\n        Example usage: ::\n\n            class Meta:\n                fields = (\"id\", \"email\", \"date_created\")\n                exclude = (\"password\", \"secret_attribute\")\n\n        Available options:\n\n        - ``fields``: Tuple or list of fields to include in the serialized result.\n        - ``additional``: Tuple or list of fields to include *in addition* to the\n            explicitly declared fields. ``additional`` and ``fields`` are\n            mutually-exclusive options.\n        - ``include``: Dictionary of additional fields to include in the schema. It is\n            usually better to define fields as class variables, but you may need to\n            use this option, e.g., if your fields are Python keywords. May be an\n            `OrderedDict`.\n        - ``exclude``: Tuple or list of fields to exclude in the serialized result.\n            Nested fields can be represented with dot delimiters.\n        - ``dateformat``: Date format for all DateTime fields that do not have their\n            date format explicitly specified.\n        - ``strict``: If `True`, raise errors during marshalling rather than\n            storing them.\n        - ``json_module``: JSON module to use for `loads` and `dumps`.\n            Defaults to the ``json`` module in the stdlib.\n        - ``ordered``: If `True`, order serialization output according to the\n            order in which fields were declared. Output of `Schema.dump` will be a\n            `collections.OrderedDict`.\n        - ``index_errors``: If `True`, errors dictionaries will include the index\n            of invalid items in a collection.\n        - ``load_only``: Tuple or list of fields to exclude from serialized results.\n        - ``dump_only``: Tuple or list of fields to exclude from deserialization\n        \"\"\"\n        pass\n\n    def __init__(self, extra=None, only=None, exclude=(), prefix='', strict=None,\n                 many=False, context=None, load_only=(), dump_only=(),\n                 partial=False):\n        # copy declared fields from metaclass\n        self.declared_fields = copy.deepcopy(self._declared_fields)\n        self.many = many\n        self.only = only\n        self.exclude = set(self.opts.exclude) | set(exclude)\n        if prefix:\n            warnings.warn(\n                'The `prefix` argument is deprecated. Use a post_dump '\n                'method to insert a prefix instead.',\n                RemovedInMarshmallow3Warning\n            )\n        self.prefix = prefix\n        self.strict = strict if strict is not None else self.opts.strict\n        self.ordered = self.opts.ordered\n        self.load_only = set(load_only) or set(self.opts.load_only)\n        self.dump_only = set(dump_only) or set(self.opts.dump_only)\n        self.partial = partial\n        #: Dictionary mapping field_names -> :class:`Field` objects\n        self.fields = self.dict_class()\n        if extra:\n            warnings.warn(\n                'The `extra` argument is deprecated. Use a post_dump '\n                'method to add additional data instead.',\n                RemovedInMarshmallow3Warning\n            )\n        self.extra = extra\n        self.context = context or {}\n        self._normalize_nested_options()\n        self._types_seen = set()\n        self._update_fields(many=many)\n\n    def __repr__(self):\n        return '<{ClassName}(many={self.many}, strict={self.strict})>'.format(\n            ClassName=self.__class__.__name__, self=self\n        )\n\n    def _postprocess(self, data, many, obj):\n        if self.extra:\n            if many:\n                for each in data:\n                    each.update(self.extra)\n            else:\n                data.update(self.extra)\n        return data\n\n    @property\n    def dict_class(self):\n        return OrderedDict if self.ordered else dict\n\n    @property\n    def set_class(self):\n        return OrderedSet if self.ordered else set\n\n    ##### Override-able methods #####\n\n    def handle_error(self, error, data):\n        \"\"\"Custom error handler function for the schema.\n\n        :param ValidationError error: The `ValidationError` raised during (de)serialization.\n        :param data: The original input data.\n\n        .. versionadded:: 2.0.0\n        \"\"\"\n        pass\n\n    def get_attribute(self, attr, obj, default):\n        \"\"\"Defines how to pull values from an object to serialize.\n\n        .. versionadded:: 2.0.0\n        \"\"\"\n        return utils.get_value(attr, obj, default)\n\n    ##### Handler decorators (deprecated) #####\n\n    @classmethod\n    def error_handler(cls, func):\n        \"\"\"Decorator that registers an error handler function for the schema.\n        The function receives the :class:`Schema` instance, a dictionary of errors,\n        and the serialized object (if serializing data) or data dictionary (if\n        deserializing data) as arguments.\n\n        Example: ::\n\n            class UserSchema(Schema):\n                email = fields.Email()\n\n            @UserSchema.error_handler\n            def handle_errors(schema, errors, obj):\n                raise ValueError('An error occurred while marshalling {}'.format(obj))\n\n            user = User(email='invalid')\n            UserSchema().dump(user)  # => raises ValueError\n            UserSchema().load({'email': 'bademail'})  # raises ValueError\n\n        .. versionadded:: 0.7.0\n        .. deprecated:: 2.0.0\n            Set the ``error_handler`` class Meta option instead.\n        \"\"\"\n        warnings.warn(\n            'Schema.error_handler is deprecated. Set the error_handler class Meta option '\n            'instead.', category=DeprecationWarning\n        )\n        cls.__error_handler__ = func\n        return func\n\n    @classmethod\n    def accessor(cls, func):\n        \"\"\"Decorator that registers a function for pulling values from an object\n        to serialize. The function receives the :class:`Schema` instance, the\n        ``key`` of the value to get, the ``obj`` to serialize, and an optional\n        ``default`` value.\n\n        .. deprecated:: 2.0.0\n            Set the ``error_handler`` class Meta option instead.\n        \"\"\"\n        warnings.warn(\n            'Schema.accessor is deprecated. Set the accessor class Meta option '\n            'instead.', category=DeprecationWarning\n        )\n        cls.__accessor__ = func\n        return func\n\n    ##### Serialization/Deserialization API #####\n\n    def dump(self, obj, many=None, update_fields=True, **kwargs):\n        \"\"\"Serialize an object to native Python data types according to this\n        Schema's fields.\n\n        :param obj: The object to serialize.\n        :param bool many: Whether to serialize `obj` as a collection. If `None`, the value\n            for `self.many` is used.\n        :param bool update_fields: Whether to update the schema's field classes. Typically\n            set to `True`, but may be `False` when serializing a homogenous collection.\n            This parameter is used by `fields.Nested` to avoid multiple updates.\n        :return: A tuple of the form (``data``, ``errors``)\n        :rtype: `MarshalResult`, a `collections.namedtuple`\n\n        .. versionadded:: 1.0.0\n        \"\"\"\n        # Callable marshalling object\n        marshal = marshalling.Marshaller(prefix=self.prefix)\n        errors = {}\n        many = self.many if many is None else bool(many)\n        if many and utils.is_iterable_but_not_string(obj):\n            obj = list(obj)\n\n        if self._has_processors:\n            try:\n                processed_obj = self._invoke_dump_processors(\n                    PRE_DUMP,\n                    obj,\n                    many,\n                    original_data=obj)\n            except ValidationError as error:\n                errors = error.normalized_messages()\n                result = None\n        else:\n            processed_obj = obj\n\n        if not errors:\n            if update_fields:\n                obj_type = type(processed_obj)\n                if obj_type not in self._types_seen:\n                    self._update_fields(processed_obj, many=many)\n                    if not isinstance(processed_obj, Mapping):\n                        self._types_seen.add(obj_type)\n\n            try:\n                preresult = marshal(\n                    processed_obj,\n                    self.fields,\n                    many=many,\n                    # TODO: Remove self.__accessor__ in a later release\n                    accessor=self.get_attribute or self.__accessor__,\n                    dict_class=self.dict_class,\n                    index_errors=self.opts.index_errors,\n                    **kwargs\n                )\n            except ValidationError as error:\n                errors = marshal.errors\n                preresult = error.data\n\n            result = self._postprocess(preresult, many, obj=obj)\n\n        if not errors and self._has_processors:\n            try:\n                result = self._invoke_dump_processors(\n                    POST_DUMP,\n                    result,\n                    many,\n                    original_data=obj)\n            except ValidationError as error:\n                errors = error.normalized_messages()\n        if errors:\n            # TODO: Remove self.__error_handler__ in a later release\n            if self.__error_handler__ and callable(self.__error_handler__):\n                self.__error_handler__(errors, obj)\n            exc = ValidationError(\n                errors,\n                field_names=marshal.error_field_names,\n                fields=marshal.error_fields,\n                data=obj,\n                **marshal.error_kwargs\n            )\n            self.handle_error(exc, obj)\n            if self.strict:\n                raise exc\n\n        return MarshalResult(result, errors)\n\n    def dumps(self, obj, many=None, update_fields=True, *args, **kwargs):\n        \"\"\"Same as :meth:`dump`, except return a JSON-encoded string.\n\n        :param obj: The object to serialize.\n        :param bool many: Whether to serialize `obj` as a collection. If `None`, the value\n            for `self.many` is used.\n        :param bool update_fields: Whether to update the schema's field classes. Typically\n            set to `True`, but may be `False` when serializing a homogenous collection.\n            This parameter is used by `fields.Nested` to avoid multiple updates.\n        :return: A tuple of the form (``data``, ``errors``)\n        :rtype: `MarshalResult`, a `collections.namedtuple`\n\n        .. versionadded:: 1.0.0\n        \"\"\"\n        deserialized, errors = self.dump(obj, many=many, update_fields=update_fields)\n        ret = self.opts.json_module.dumps(deserialized, *args, **kwargs)\n        return MarshalResult(ret, errors)\n\n    def load(self, data, many=None, partial=None):\n        \"\"\"Deserialize a data structure to an object defined by this Schema's\n        fields and :meth:`make_object`.\n\n        :param dict data: The data to deserialize.\n        :param bool many: Whether to deserialize `data` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to ignore missing fields. If `None`,\n            the value for `self.partial` is used. If its value is an iterable,\n            only missing fields listed in that iterable will be ignored.\n        :return: A tuple of the form (``data``, ``errors``)\n        :rtype: `UnmarshalResult`, a `collections.namedtuple`\n\n        .. versionadded:: 1.0.0\n        \"\"\"\n        result, errors = self._do_load(data, many, partial=partial, postprocess=True)\n        return UnmarshalResult(data=result, errors=errors)\n\n    def loads(self, json_data, many=None, *args, **kwargs):\n        \"\"\"Same as :meth:`load`, except it takes a JSON string as input.\n\n        :param str json_data: A JSON string of the data to deserialize.\n        :param bool many: Whether to deserialize `obj` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to ignore missing fields. If `None`,\n            the value for `self.partial` is used. If its value is an iterable,\n            only missing fields listed in that iterable will be ignored.\n        :return: A tuple of the form (``data``, ``errors``)\n        :rtype: `UnmarshalResult`, a `collections.namedtuple`\n\n        .. versionadded:: 1.0.0\n        \"\"\"\n        # TODO: This avoids breaking backward compatibility if people were\n        # passing in positional args after `many` for use by `json.loads`, but\n        # ideally we shouldn't have to do this.\n        partial = kwargs.pop('partial', None)\n\n        data = self.opts.json_module.loads(json_data, *args, **kwargs)\n        return self.load(data, many=many, partial=partial)\n\n    def validate(self, data, many=None, partial=None):\n        \"\"\"Validate `data` against the schema, returning a dictionary of\n        validation errors.\n\n        :param dict data: The data to validate.\n        :param bool many: Whether to validate `data` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to ignore missing fields. If `None`,\n            the value for `self.partial` is used. If its value is an iterable,\n            only missing fields listed in that iterable will be ignored.\n        :return: A dictionary of validation errors.\n        :rtype: dict\n\n        .. versionadded:: 1.1.0\n        \"\"\"\n        _, errors = self._do_load(data, many, partial=partial, postprocess=False)\n        return errors\n\n    ##### Private Helpers #####\n\n    def _do_load(self, data, many=None, partial=None, postprocess=True):\n        \"\"\"Deserialize `data`, returning the deserialized result and a dictonary of\n        validation errors.\n\n        :param data: The data to deserialize.\n        :param bool many: Whether to deserialize `data` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to validate required fields. If its value is an iterable,\n            only fields listed in that iterable will be ignored will be allowed missing.\n            If `True`, all fields will be allowed missing.\n            If `None`, the value for `self.partial` is used.\n        :param bool postprocess: Whether to run post_load methods..\n        :return: A tuple of the form (`data`, `errors`)\n        \"\"\"\n        # Callable unmarshalling object\n        unmarshal = marshalling.Unmarshaller()\n        errors = {}\n        many = self.many if many is None else bool(many)\n        if partial is None:\n            partial = self.partial\n        try:\n            processed_data = self._invoke_load_processors(\n                PRE_LOAD,\n                data,\n                many,\n                original_data=data)\n        except ValidationError as err:\n            errors = err.normalized_messages()\n            result = None\n        if not errors:\n            try:\n                result = unmarshal(\n                    processed_data,\n                    self.fields,\n                    many=many,\n                    partial=partial,\n                    dict_class=self.dict_class,\n                    index_errors=self.opts.index_errors,\n                )\n            except ValidationError as error:\n                result = error.data\n            self._invoke_field_validators(unmarshal, data=result, many=many)\n            errors = unmarshal.errors\n            field_errors = bool(errors)\n            # Run schema-level migration\n            try:\n                self._invoke_validators(unmarshal, pass_many=True, data=result, original_data=data,\n                                        many=many, field_errors=field_errors)\n            except ValidationError as err:\n                errors.update(err.messages)\n            try:\n                self._invoke_validators(unmarshal, pass_many=False, data=result, original_data=data,\n                                        many=many, field_errors=field_errors)\n            except ValidationError as err:\n                errors.update(err.messages)\n        # Run post processors\n        if not errors and postprocess:\n            try:\n                result = self._invoke_load_processors(\n                    POST_LOAD,\n                    result,\n                    many,\n                    original_data=data)\n            except ValidationError as err:\n                errors = err.normalized_messages()\n        if errors:\n            # TODO: Remove self.__error_handler__ in a later release\n            if self.__error_handler__ and callable(self.__error_handler__):\n                self.__error_handler__(errors, data)\n            exc = ValidationError(\n                errors,\n                field_names=unmarshal.error_field_names,\n                fields=unmarshal.error_fields,\n                data=data,\n                **unmarshal.error_kwargs\n            )\n            self.handle_error(exc, data)\n            if self.strict:\n                raise exc\n\n        return result, errors\n\n    def _normalize_nested_options(self):\n        \"\"\"Apply then flatten nested schema options\"\"\"\n        if self.only is not None:\n            # Apply the only option to nested fields.\n            self.__apply_nested_option('only', self.only, 'intersection')\n            # Remove the child field names from the only option.\n            self.only = self.set_class(\n                [field.split('.', 1)[0] for field in self.only],\n            )\n        if self.exclude:\n            # Apply the exclude option to nested fields.\n            self.__apply_nested_option('exclude', self.exclude, 'union')\n            # Remove the parent field names from the exclude option.\n            self.exclude = self.set_class(\n                [field for field in self.exclude if '.' not in field],\n            )\n\n    def __apply_nested_option(self, option_name, field_names, set_operation):\n        \"\"\"Apply nested options to nested fields\"\"\"\n        # Split nested field names on the first dot.\n        nested_fields = [name.split('.', 1) for name in field_names if '.' in name]\n        # Partition the nested field names by parent field.\n        nested_options = defaultdict(list)\n        for parent, nested_names in nested_fields:\n            nested_options[parent].append(nested_names)\n        # Apply the nested field options.\n        for key, options in iter(nested_options.items()):\n            new_options = self.set_class(options)\n            original_options = getattr(self.declared_fields[key], option_name, ())\n            if original_options:\n                if set_operation == 'union':\n                    new_options |= self.set_class(original_options)\n                if set_operation == 'intersection':\n                    new_options &= self.set_class(original_options)\n            setattr(self.declared_fields[key], option_name, new_options)\n\n    def _update_fields(self, obj=None, many=False):\n        \"\"\"Update fields based on the passed in object.\"\"\"\n        if self.only is not None:\n            # Return only fields specified in only option\n            if self.opts.fields:\n                field_names = self.set_class(self.opts.fields) & self.set_class(self.only)\n            else:\n                field_names = self.set_class(self.only)\n        elif self.opts.fields:\n            # Return fields specified in fields option\n            field_names = self.set_class(self.opts.fields)\n        elif self.opts.additional:\n            # Return declared fields + additional fields\n            field_names = (self.set_class(self.declared_fields.keys()) |\n                            self.set_class(self.opts.additional))\n        else:\n            field_names = self.set_class(self.declared_fields.keys())\n\n        # If \"exclude\" option or param is specified, remove those fields\n        field_names -= self.exclude\n        ret = self.__filter_fields(field_names, obj, many=many)\n        # Set parents\n        self.__set_field_attrs(ret)\n        self.fields = ret\n        return self.fields\n\n    def on_bind_field(self, field_name, field_obj):\n        \"\"\"Hook to modify a field when it is bound to the `Schema`. No-op by default.\"\"\"\n        return None\n\n    def __set_field_attrs(self, fields_dict):\n        \"\"\"Bind fields to the schema, setting any necessary attributes\n        on the fields (e.g. parent and name).\n\n        Also set field load_only and dump_only values if field_name was\n        specified in ``class Meta``.\n        \"\"\"\n        for field_name, field_obj in iteritems(fields_dict):\n            try:\n                if field_name in self.load_only:\n                    field_obj.load_only = True\n                if field_name in self.dump_only:\n                    field_obj.dump_only = True\n                field_obj._add_to_schema(field_name, self)\n                self.on_bind_field(field_name, field_obj)\n            except TypeError:\n                # field declared as a class, not an instance\n                if (isinstance(field_obj, type) and\n                        issubclass(field_obj, base.FieldABC)):\n                    msg = ('Field for \"{0}\" must be declared as a '\n                           'Field instance, not a class. '\n                           'Did you mean \"fields.{1}()\"?'\n                           .format(field_name, field_obj.__name__))\n                    raise TypeError(msg)\n        return fields_dict\n\n    def __filter_fields(self, field_names, obj, many=False):\n        \"\"\"Return only those field_name:field_obj pairs specified by\n        ``field_names``.\n\n        :param set field_names: Field names to include in the final\n            return dictionary.\n        :param object|Mapping|list obj The object to base filtered fields on.\n        :returns: An dict of field_name:field_obj pairs.\n        \"\"\"\n        if obj and many:\n            try:  # list\n                obj = obj[0]\n            except IndexError:  # Nothing to serialize\n                return dict((k, v) for k, v in self.declared_fields.items() if k in field_names)\n        ret = self.dict_class()\n        for key in field_names:\n            if key in self.declared_fields:\n                ret[key] = self.declared_fields[key]\n            else:  # Implicit field creation (class Meta 'fields' or 'additional')\n                if obj:\n                    attribute_type = None\n                    try:\n                        if isinstance(obj, Mapping):\n                            attribute_type = type(obj[key])\n                        else:\n                            attribute_type = type(getattr(obj, key))\n                    except (AttributeError, KeyError) as err:\n                        err_type = type(err)\n                        raise err_type(\n                            '\"{0}\" is not a valid field for {1}.'.format(key, obj))\n                    field_obj = self.TYPE_MAPPING.get(attribute_type, fields.Field)()\n                else:  # Object is None\n                    field_obj = fields.Field()\n                # map key -> field (default to Raw)\n                ret[key] = field_obj\n        return ret\n\n    def _invoke_dump_processors(self, tag_name, data, many, original_data=None):\n        # The pass_many post-dump processors may do things like add an envelope, so\n        # invoke those after invoking the non-pass_many processors which will expect\n        # to get a list of items.\n        data = self._invoke_processors(tag_name, pass_many=False,\n            data=data, many=many, original_data=original_data)\n        data = self._invoke_processors(tag_name, pass_many=True,\n            data=data, many=many, original_data=original_data)\n        return data\n\n    def _invoke_load_processors(self, tag_name, data, many, original_data=None):\n        # This has to invert the order of the dump processors, so run the pass_many\n        # processors first.\n        data = self._invoke_processors(tag_name, pass_many=True,\n            data=data, many=many, original_data=original_data)\n        data = self._invoke_processors(tag_name, pass_many=False,\n            data=data, many=many, original_data=original_data)\n        return data\n\n    def _invoke_field_validators(self, unmarshal, data, many):\n        for attr_name in self.__processors__[(VALIDATES, False)]:\n            validator = getattr(self, attr_name)\n            validator_kwargs = validator.__marshmallow_kwargs__[(VALIDATES, False)]\n            field_name = validator_kwargs['field_name']\n\n            try:\n                field_obj = self.fields[field_name]\n            except KeyError:\n                if field_name in self.declared_fields:\n                    continue\n                raise ValueError('\"{0}\" field does not exist.'.format(field_name))\n\n            if many:\n                for idx, item in enumerate(data):\n                    try:\n                        value = item[field_obj.attribute or field_name]\n                    except KeyError:\n                        pass\n                    else:\n                        validated_value = unmarshal.call_and_store(\n                            getter_func=validator,\n                            data=value,\n                            field_name=field_obj.load_from or field_name,\n                            field_obj=field_obj,\n                            index=(idx if self.opts.index_errors else None)\n                        )\n                        if validated_value is missing:\n                            data[idx].pop(field_name, None)\n            else:\n                try:\n                    value = data[field_obj.attribute or field_name]\n                except KeyError:\n                    pass\n                else:\n                    validated_value = unmarshal.call_and_store(\n                        getter_func=validator,\n                        data=value,\n                        field_name=field_obj.load_from or field_name,\n                        field_obj=field_obj\n                    )\n                    if validated_value is missing:\n                        data.pop(field_name, None)\n\n    def _invoke_validators(\n            self, unmarshal, pass_many, data, original_data, many, field_errors=False):\n        errors = {}\n        for attr_name in self.__processors__[(VALIDATES_SCHEMA, pass_many)]:\n            validator = getattr(self, attr_name)\n            validator_kwargs = validator.__marshmallow_kwargs__[(VALIDATES_SCHEMA, pass_many)]\n            pass_original = validator_kwargs.get('pass_original', False)\n\n            skip_on_field_errors = validator_kwargs['skip_on_field_errors']\n            if skip_on_field_errors and field_errors:\n                continue\n\n            if pass_many:\n                validator = functools.partial(validator, many=many)\n            if many and not pass_many:\n                for idx, item in enumerate(data):\n                    try:\n                        unmarshal.run_validator(validator,\n                                                item, original_data, self.fields, many=many,\n                                                index=idx, pass_original=pass_original)\n                    except ValidationError as err:\n                        errors.update(err.messages)\n            else:\n                try:\n                    unmarshal.run_validator(validator,\n                                            data, original_data, self.fields, many=many,\n                                            pass_original=pass_original)\n                except ValidationError as err:\n                    errors.update(err.messages)\n        if errors:\n            raise ValidationError(errors)\n        return None\n\n    def _invoke_processors(self, tag_name, pass_many, data, many, original_data=None):\n        for attr_name in self.__processors__[(tag_name, pass_many)]:\n            # This will be a bound method.\n            processor = getattr(self, attr_name)\n\n            processor_kwargs = processor.__marshmallow_kwargs__[(tag_name, pass_many)]\n            pass_original = processor_kwargs.get('pass_original', False)\n\n            if pass_many:\n                if pass_original:\n                    data = utils.if_none(processor(data, many, original_data), data)\n                else:\n                    data = utils.if_none(processor(data, many), data)\n            elif many:\n                if pass_original:\n                    data = [utils.if_none(processor(item, original_data), item)\n                            for item in data]\n                else:\n                    data = [utils.if_none(processor(item), item) for item in data]\n            else:\n                if pass_original:\n                    data = utils.if_none(processor(data, original_data), data)\n                else:\n                    data = utils.if_none(processor(data), data)\n        return data\n\n\nclass Schema(with_metaclass(SchemaMeta, BaseSchema)):\n    __doc__ = BaseSchema.__doc__\n","new_file_content":"\"\"\"The :class:`Schema` class, including its metaclass and options (class Meta).\"\"\"\nfrom collections import defaultdict, OrderedDict\nfrom collections.abc import Mapping\nfrom functools import lru_cache\nimport datetime as dt\nimport uuid\nimport decimal\nimport copy\nimport inspect\nimport json\nimport typing\nimport warnings\n\nfrom marshmallow import base, fields as ma_fields, class_registry\nfrom marshmallow.error_store import ErrorStore\nfrom marshmallow.exceptions import ValidationError, StringNotCollectionError\nfrom marshmallow.orderedset import OrderedSet\nfrom marshmallow.decorators import (\n    POST_DUMP,\n    POST_LOAD,\n    PRE_DUMP,\n    PRE_LOAD,\n    VALIDATES,\n    VALIDATES_SCHEMA,\n)\nfrom marshmallow.utils import (\n    RAISE,\n    EXCLUDE,\n    INCLUDE,\n    missing,\n    set_value,\n    get_value,\n    is_collection,\n    is_instance_or_subclass,\n    is_iterable_but_not_string,\n)\n\n\ndef _get_fields(attrs, field_class, pop=False, ordered=False):\n    \"\"\"Get fields from a class. If ordered=True, fields will sorted by creation index.\n\n    :param attrs: Mapping of class attributes\n    :param type field_class: Base field class\n    :param bool pop: Remove matching fields\n    \"\"\"\n    fields = [\n        (field_name, field_value)\n        for field_name, field_value in attrs.items()\n        if is_instance_or_subclass(field_value, field_class)\n    ]\n    if pop:\n        for field_name, _ in fields:\n            del attrs[field_name]\n    if ordered:\n        fields.sort(key=lambda pair: pair[1]._creation_index)\n    return fields\n\n\n# This function allows Schemas to inherit from non-Schema classes and ensures\n#   inheritance according to the MRO\ndef _get_fields_by_mro(klass, field_class, ordered=False):\n    \"\"\"Collect fields from a class, following its method resolution order. The\n    class itself is excluded from the search; only its parents are checked. Get\n    fields from ``_declared_fields`` if available, else use ``__dict__``.\n\n    :param type klass: Class whose fields to retrieve\n    :param type field_class: Base field class\n    \"\"\"\n    mro = inspect.getmro(klass)\n    # Loop over mro in reverse to maintain correct order of fields\n    return sum(\n        (\n            _get_fields(\n                getattr(base, \"_declared_fields\", base.__dict__),\n                field_class,\n                ordered=ordered,\n            )\n            for base in mro[:0:-1]\n        ),\n        [],\n    )\n\n\nclass SchemaMeta(type):\n    \"\"\"Metaclass for the Schema class. Binds the declared fields to\n    a ``_declared_fields`` attribute, which is a dictionary mapping attribute\n    names to field objects. Also sets the ``opts`` class attribute, which is\n    the Schema class's ``class Meta`` options.\n    \"\"\"\n\n    def __new__(mcs, name, bases, attrs):\n        meta = attrs.get(\"Meta\")\n        ordered = getattr(meta, \"ordered\", False)\n        if not ordered:\n            # Inherit 'ordered' option\n            # Warning: We loop through bases instead of MRO because we don't\n            # yet have access to the class object\n            # (i.e. can't call super before we have fields)\n            for base_ in bases:\n                if hasattr(base_, \"Meta\") and hasattr(base_.Meta, \"ordered\"):\n                    ordered = base_.Meta.ordered\n                    break\n            else:\n                ordered = False\n        cls_fields = _get_fields(attrs, base.FieldABC, pop=True, ordered=ordered)\n        klass = super().__new__(mcs, name, bases, attrs)\n        inherited_fields = _get_fields_by_mro(klass, base.FieldABC, ordered=ordered)\n\n        meta = klass.Meta\n        # Set klass.opts in __new__ rather than __init__ so that it is accessible in\n        # get_declared_fields\n        klass.opts = klass.OPTIONS_CLASS(meta, ordered=ordered)\n        # Add fields specified in the `include` class Meta option\n        cls_fields += list(klass.opts.include.items())\n\n        dict_cls = OrderedDict if ordered else dict\n        # Assign _declared_fields on class\n        klass._declared_fields = mcs.get_declared_fields(\n            klass=klass,\n            cls_fields=cls_fields,\n            inherited_fields=inherited_fields,\n            dict_cls=dict_cls,\n        )\n        return klass\n\n    @classmethod\n    def get_declared_fields(mcs, klass, cls_fields, inherited_fields, dict_cls):\n        \"\"\"Returns a dictionary of field_name => `Field` pairs declard on the class.\n        This is exposed mainly so that plugins can add additional fields, e.g. fields\n        computed from class Meta options.\n\n        :param type klass: The class object.\n        :param list cls_fields: The fields declared on the class, including those added\n            by the ``include`` class Meta option.\n        :param list inherited_fields: Inherited fields.\n        :param type dict_class: Either `dict` or `OrderedDict`, depending on the whether\n            the user specified `ordered=True`.\n        \"\"\"\n        return dict_cls(inherited_fields + cls_fields)\n\n    def __init__(cls, name, bases, attrs):\n        super().__init__(cls, bases, attrs)\n        if name and cls.opts.register:\n            class_registry.register(name, cls)\n        cls._hooks = cls.resolve_hooks()\n\n    def resolve_hooks(cls):\n        \"\"\"Add in the decorated processors\n\n        By doing this after constructing the class, we let standard inheritance\n        do all the hard work.\n        \"\"\"\n        mro = inspect.getmro(cls)\n\n        hooks = defaultdict(list)\n\n        for attr_name in dir(cls):\n            # Need to look up the actual descriptor, not whatever might be\n            # bound to the class. This needs to come from the __dict__ of the\n            # declaring class.\n            for parent in mro:\n                try:\n                    attr = parent.__dict__[attr_name]\n                except KeyError:\n                    continue\n                else:\n                    break\n            else:\n                # In case we didn't find the attribute and didn't break above.\n                # We should never hit this - it's just here for completeness\n                # to exclude the possibility of attr being undefined.\n                continue\n\n            try:\n                hook_config = attr.__marshmallow_hook__\n            except AttributeError:\n                pass\n            else:\n                for key in hook_config.keys():\n                    # Use name here so we can get the bound method later, in\n                    # case the processor was a descriptor or something.\n                    hooks[key].append(attr_name)\n\n        return hooks\n\n\nclass SchemaOpts:\n    \"\"\"class Meta options for the :class:`Schema`. Defines defaults.\"\"\"\n\n    def __init__(self, meta, ordered=False):\n        self.fields = getattr(meta, \"fields\", ())\n        if not isinstance(self.fields, (list, tuple)):\n            raise ValueError(\"`fields` option must be a list or tuple.\")\n        self.additional = getattr(meta, \"additional\", ())\n        if not isinstance(self.additional, (list, tuple)):\n            raise ValueError(\"`additional` option must be a list or tuple.\")\n        if self.fields and self.additional:\n            raise ValueError(\n                \"Cannot set both `fields` and `additional` options\"\n                \" for the same Schema.\"\n            )\n        self.exclude = getattr(meta, \"exclude\", ())\n        if not isinstance(self.exclude, (list, tuple)):\n            raise ValueError(\"`exclude` must be a list or tuple.\")\n        self.dateformat = getattr(meta, \"dateformat\", None)\n        self.datetimeformat = getattr(meta, \"datetimeformat\", None)\n        if hasattr(meta, \"json_module\"):\n            warnings.warn(\n                \"The json_module class Meta option is deprecated. Use render_module instead.\",\n                DeprecationWarning,\n            )\n            render_module = getattr(meta, \"json_module\", json)\n        else:\n            render_module = json\n        self.render_module = getattr(meta, \"render_module\", render_module)\n        self.ordered = getattr(meta, \"ordered\", ordered)\n        self.index_errors = getattr(meta, \"index_errors\", True)\n        self.include = getattr(meta, \"include\", {})\n        self.load_only = getattr(meta, \"load_only\", ())\n        self.dump_only = getattr(meta, \"dump_only\", ())\n        self.unknown = getattr(meta, \"unknown\", RAISE)\n        self.register = getattr(meta, \"register\", True)\n\n\nclass BaseSchema(base.SchemaABC):\n    \"\"\"Base schema class with which to define custom schemas.\n\n    Example usage:\n\n    .. code-block:: python\n\n        import datetime as dt\n        from marshmallow import Schema, fields\n\n        class Album:\n            def __init__(self, title, release_date):\n                self.title = title\n                self.release_date = release_date\n\n        class AlbumSchema(Schema):\n            title = fields.Str()\n            release_date = fields.Date()\n\n        # Or, equivalently\n        class AlbumSchema2(Schema):\n            class Meta:\n                fields = (\"title\", \"release_date\")\n\n        album = Album(\"Beggars Banquet\", dt.date(1968, 12, 6))\n        schema = AlbumSchema()\n        data = schema.dump(album)\n        data  # {'release_date': '1968-12-06', 'title': 'Beggars Banquet'}\n\n    :param tuple|list only: Whitelist of the declared fields to select when\n        instantiating the Schema. If None, all fields are used. Nested fields\n        can be represented with dot delimiters.\n    :param tuple|list exclude: Blacklist of the declared fields to exclude\n        when instantiating the Schema. If a field appears in both `only` and\n        `exclude`, it is not used. Nested fields can be represented with dot\n        delimiters.\n    :param bool many: Should be set to `True` if ``obj`` is a collection\n        so that the object will be serialized to a list.\n    :param dict context: Optional context passed to :class:`fields.Method` and\n        :class:`fields.Function` fields.\n    :param tuple|list load_only: Fields to skip during serialization (write-only fields)\n    :param tuple|list dump_only: Fields to skip during deserialization (read-only fields)\n    :param bool|tuple partial: Whether to ignore missing fields and not require\n        any fields declared. Propagates down to ``Nested`` fields as well. If\n        its value is an iterable, only missing fields listed in that iterable\n        will be ignored. Use dot delimiters to specify nested fields.\n    :param unknown: Whether to exclude, include, or raise an error for unknown\n        fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.\n\n    .. versionchanged:: 3.0.0\n        `prefix` parameter removed.\n\n    .. versionchanged:: 2.0.0\n        `__validators__`, `__preprocessors__`, and `__data_handlers__` are removed in favor of\n        `marshmallow.decorators.validates_schema`,\n        `marshmallow.decorators.pre_load` and `marshmallow.decorators.post_dump`.\n        `__accessor__` and `__error_handler__` are deprecated. Implement the\n        `handle_error` and `get_attribute` methods instead.\n    \"\"\"\n\n    TYPE_MAPPING = {\n        str: ma_fields.String,\n        bytes: ma_fields.String,\n        dt.datetime: ma_fields.DateTime,\n        float: ma_fields.Float,\n        bool: ma_fields.Boolean,\n        tuple: ma_fields.Raw,\n        list: ma_fields.Raw,\n        set: ma_fields.Raw,\n        int: ma_fields.Integer,\n        uuid.UUID: ma_fields.UUID,\n        dt.time: ma_fields.Time,\n        dt.date: ma_fields.Date,\n        dt.timedelta: ma_fields.TimeDelta,\n        decimal.Decimal: ma_fields.Decimal,\n    }\n    #: Overrides for default schema-level error messages\n    error_messages = {}\n\n    _default_error_messages = {\n        \"type\": \"Invalid input type.\",\n        \"unknown\": \"Unknown field.\",\n    }\n\n    OPTIONS_CLASS = SchemaOpts\n\n    class Meta:\n        \"\"\"Options object for a Schema.\n\n        Example usage: ::\n\n            class Meta:\n                fields = (\"id\", \"email\", \"date_created\")\n                exclude = (\"password\", \"secret_attribute\")\n\n        Available options:\n\n        - ``fields``: Tuple or list of fields to include in the serialized result.\n        - ``additional``: Tuple or list of fields to include *in addition* to the\n            explicitly declared fields. ``additional`` and ``fields`` are\n            mutually-exclusive options.\n        - ``include``: Dictionary of additional fields to include in the schema. It is\n            usually better to define fields as class variables, but you may need to\n            use this option, e.g., if your fields are Python keywords. May be an\n            `OrderedDict`.\n        - ``exclude``: Tuple or list of fields to exclude in the serialized result.\n            Nested fields can be represented with dot delimiters.\n        - ``dateformat``: Default format for `Date <fields.Date>` fields.\n        - ``datetimeformat``: Default format for `DateTime <fields.DateTime>` fields.\n        - ``render_module``: Module to use for `loads <Schema.loads>` and `dumps <Schema.dumps>`.\n            Defaults to `json` from the standard library.\n        - ``ordered``: If `True`, order serialization output according to the\n            order in which fields were declared. Output of `Schema.dump` will be a\n            `collections.OrderedDict`.\n        - ``index_errors``: If `True`, errors dictionaries will include the index\n            of invalid items in a collection.\n        - ``load_only``: Tuple or list of fields to exclude from serialized results.\n        - ``dump_only``: Tuple or list of fields to exclude from deserialization\n        - ``unknown``: Whether to exclude, include, or raise an error for unknown\n            fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.\n        - ``register``: Whether to register the `Schema` with marshmallow's internal\n            class registry. Must be `True` if you intend to refer to this `Schema`\n            by class name in `Nested` fields. Only set this to `False` when memory\n            usage is critical. Defaults to `True`.\n        \"\"\"\n\n        pass\n\n    def __init__(\n        self,\n        *,\n        only=None,\n        exclude=(),\n        many=False,\n        context=None,\n        load_only=(),\n        dump_only=(),\n        partial=False,\n        unknown=None\n    ):\n        # Raise error if only or exclude is passed as string, not list of strings\n        if only is not None and not is_collection(only):\n            raise StringNotCollectionError('\"only\" should be a list of strings')\n        if exclude is not None and not is_collection(exclude):\n            raise StringNotCollectionError('\"exclude\" should be a list of strings')\n        # copy declared fields from metaclass\n        self.declared_fields = copy.deepcopy(self._declared_fields)\n        self.many = many\n        self.only = only\n        self.exclude = set(self.opts.exclude) | set(exclude)\n        self.ordered = self.opts.ordered\n        self.load_only = set(load_only) or set(self.opts.load_only)\n        self.dump_only = set(dump_only) or set(self.opts.dump_only)\n        self.partial = partial\n        self.unknown = unknown or self.opts.unknown\n        self.context = context or {}\n        self._normalize_nested_options()\n        #: Dictionary mapping field_names -> :class:`Field` objects\n        self.fields = self._init_fields()\n        self.dump_fields, self.load_fields = self.dict_class(), self.dict_class()\n        for field_name, field_obj in self.fields.items():\n            if field_obj.load_only:\n                self.load_fields[field_name] = field_obj\n            elif field_obj.dump_only:\n                self.dump_fields[field_name] = field_obj\n            else:\n                self.load_fields[field_name] = field_obj\n                self.dump_fields[field_name] = field_obj\n        messages = {}\n        messages.update(self._default_error_messages)\n        for cls in reversed(self.__class__.__mro__):\n            messages.update(getattr(cls, \"error_messages\", {}))\n        messages.update(self.error_messages or {})\n        self.error_messages = messages\n\n    def __repr__(self):\n        return \"<{ClassName}(many={self.many})>\".format(\n            ClassName=self.__class__.__name__, self=self\n        )\n\n    @property\n    def dict_class(self):\n        return OrderedDict if self.ordered else dict\n\n    @property\n    def set_class(self):\n        return OrderedSet if self.ordered else set\n\n    @classmethod\n    def from_dict(\n        cls, fields: typing.Dict[str, ma_fields.Field], *, name: str = \"GeneratedSchema\"\n    ) -> typing.Type[\"Schema\"]:\n        \"\"\"Generate a `Schema` class given a dictionary of fields.\n\n        .. code-block:: python\n\n            from marshmallow import Schema, fields\n\n            PersonSchema = Schema.from_dict({\"name\": fields.Str()})\n            print(PersonSchema().load({\"name\": \"David\"}))  # => {'name': 'David'}\n\n        Generated schemas are not added to the class registry and therefore cannot\n        be referred to by name in `Nested` fields.\n\n        :param dict fields: Dictionary mapping field names to field instances.\n        :param str name: Optional name for the class, which will appear in\n            the ``repr`` for the class.\n\n        .. versionadded:: 3.0.0\n        \"\"\"\n        attrs = fields.copy()\n        attrs[\"Meta\"] = type(\n            \"GeneratedMeta\", (getattr(cls, \"Meta\", object),), {\"register\": False}\n        )\n        schema_cls = type(name, (cls,), attrs)\n        return schema_cls\n\n    ##### Override-able methods #####\n\n    def handle_error(self, error, data, *, many, **kwargs):\n        \"\"\"Custom error handler function for the schema.\n\n        :param ValidationError error: The `ValidationError` raised during (de)serialization.\n        :param data: The original input data.\n        :param bool many: Value of ``many`` on dump or load.\n        :param bool partial: Value of ``partial`` on load.\n\n        .. versionadded:: 2.0.0\n\n        .. versionchanged:: 3.0.0rc9\n            Receives `many` and `partial` (on deserialization) as keyword arguments.\n        \"\"\"\n        pass\n\n    def get_attribute(self, obj, attr, default):\n        \"\"\"Defines how to pull values from an object to serialize.\n\n        .. versionadded:: 2.0.0\n\n        .. versionchanged:: 3.0.0a1\n            Changed position of ``obj`` and ``attr``.\n        \"\"\"\n        return get_value(obj, attr, default)\n\n    ##### Serialization/Deserialization API #####\n\n    @staticmethod\n    def _call_and_store(getter_func, data, *, field_name, error_store, index=None):\n        \"\"\"Call ``getter_func`` with ``data`` as its argument, and store any `ValidationErrors`.\n\n        :param callable getter_func: Function for getting the serialized/deserialized\n            value from ``data``.\n        :param data: The data passed to ``getter_func``.\n        :param str field_name: Field name.\n        :param int index: Index of the item being validated, if validating a collection,\n            otherwise `None`.\n        \"\"\"\n        try:\n            value = getter_func(data)\n        except ValidationError as error:\n            error_store.store_error(error.messages, field_name, index=index)\n            # When a Nested field fails validation, the marshalled data is stored\n            # on the ValidationError's valid_data attribute\n            return error.valid_data or missing\n        return value\n\n    def _serialize(self, obj, *, many=False):\n        \"\"\"Serialize ``obj``.\n\n        :param obj: The object(s) to serialize.\n        :param bool many: `True` if ``data`` should be serialized as a collection.\n        :return: A dictionary of the serialized data\n\n        .. versionchanged:: 1.0.0\n            Renamed from ``marshal``.\n        \"\"\"\n        if many and obj is not None:\n            return [self._serialize(d, many=False) for d in obj]\n        ret = self.dict_class()\n        for attr_name, field_obj in self.dump_fields.items():\n            value = field_obj.serialize(attr_name, obj, accessor=self.get_attribute)\n            if value is missing:\n                continue\n            key = field_obj.data_key or attr_name\n            ret[key] = value\n        return ret\n\n    def dump(self, obj, *, many=None):\n        \"\"\"Serialize an object to native Python data types according to this\n        Schema's fields.\n\n        :param obj: The object to serialize.\n        :param bool many: Whether to serialize `obj` as a collection. If `None`, the value\n            for `self.many` is used.\n        :return: A dict of serialized data\n        :rtype: dict\n\n        .. versionadded:: 1.0.0\n        .. versionchanged:: 3.0.0b7\n            This method returns the serialized data rather than a ``(data, errors)`` duple.\n            A :exc:`ValidationError <marshmallow.exceptions.ValidationError>` is raised\n            if ``obj`` is invalid.\n        .. versionchanged:: 3.0.0rc9\n            Validation no longer occurs upon serialization.\n        \"\"\"\n        many = self.many if many is None else bool(many)\n        if many and is_iterable_but_not_string(obj):\n            obj = list(obj)\n\n        if self._has_processors(PRE_DUMP):\n            processed_obj = self._invoke_dump_processors(\n                PRE_DUMP, obj, many=many, original_data=obj\n            )\n        else:\n            processed_obj = obj\n\n        result = self._serialize(processed_obj, many=many)\n\n        if self._has_processors(POST_DUMP):\n            result = self._invoke_dump_processors(\n                POST_DUMP, result, many=many, original_data=obj\n            )\n\n        return result\n\n    def dumps(self, obj, *args, many=None, **kwargs):\n        \"\"\"Same as :meth:`dump`, except return a JSON-encoded string.\n\n        :param obj: The object to serialize.\n        :param bool many: Whether to serialize `obj` as a collection. If `None`, the value\n            for `self.many` is used.\n        :return: A ``json`` string\n        :rtype: str\n\n        .. versionadded:: 1.0.0\n        .. versionchanged:: 3.0.0b7\n            This method returns the serialized data rather than a ``(data, errors)`` duple.\n            A :exc:`ValidationError <marshmallow.exceptions.ValidationError>` is raised\n            if ``obj`` is invalid.\n        \"\"\"\n        serialized = self.dump(obj, many=many)\n        return self.opts.render_module.dumps(serialized, *args, **kwargs)\n\n    def _deserialize(\n        self, data, *, error_store, many=False, partial=False, unknown=RAISE, index=None\n    ):\n        \"\"\"Deserialize ``data``.\n\n        :param dict data: The data to deserialize.\n        :param ErrorStore error_store: Structure to store errors.\n        :param bool many: `True` if ``data`` should be deserialized as a collection.\n        :param bool|tuple partial: Whether to ignore missing fields and not require\n            any fields declared. Propagates down to ``Nested`` fields as well. If\n            its value is an iterable, only missing fields listed in that iterable\n            will be ignored. Use dot delimiters to specify nested fields.\n        :param unknown: Whether to exclude, include, or raise an error for unknown\n            fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.\n        :param int index: Index of the item being serialized (for storing errors) if\n            serializing a collection, otherwise `None`.\n        :return: A dictionary of the deserialized data.\n        \"\"\"\n        index_errors = self.opts.index_errors\n        index = index if index_errors else None\n        if many:\n            if not is_collection(data):\n                error_store.store_error([self.error_messages[\"type\"]], index=index)\n                ret = []\n            else:\n                ret = [\n                    self._deserialize(\n                        d,\n                        error_store=error_store,\n                        many=False,\n                        partial=partial,\n                        unknown=unknown,\n                        index=idx,\n                    )\n                    for idx, d in enumerate(data)\n                ]\n            return ret\n        ret = self.dict_class()\n        # Check data is a dict\n        if not isinstance(data, Mapping):\n            error_store.store_error([self.error_messages[\"type\"]], index=index)\n        else:\n            partial_is_collection = is_collection(partial)\n            for attr_name, field_obj in self.load_fields.items():\n                field_name = field_obj.data_key or attr_name\n                raw_value = data.get(field_name, missing)\n                if raw_value is missing:\n                    # Ignore missing field if we're allowed to.\n                    if partial is True or (\n                        partial_is_collection and attr_name in partial\n                    ):\n                        continue\n                d_kwargs = {}\n                # Allow partial loading of nested schemas.\n                if partial_is_collection:\n                    prefix = field_name + \".\"\n                    len_prefix = len(prefix)\n                    sub_partial = [\n                        f[len_prefix:] for f in partial if f.startswith(prefix)\n                    ]\n                    d_kwargs[\"partial\"] = sub_partial\n                else:\n                    d_kwargs[\"partial\"] = partial\n                getter = lambda val: field_obj.deserialize(\n                    val, field_name, data, **d_kwargs\n                )\n                value = self._call_and_store(\n                    getter_func=getter,\n                    data=raw_value,\n                    field_name=field_name,\n                    error_store=error_store,\n                    index=index,\n                )\n                if value is not missing:\n                    key = field_obj.attribute or attr_name\n                    set_value(ret, key, value)\n            if unknown != EXCLUDE:\n                fields = {\n                    field_obj.data_key or field_name\n                    for field_name, field_obj in self.load_fields.items()\n                }\n                for key in set(data) - fields:\n                    value = data[key]\n                    if unknown == INCLUDE:\n                        set_value(ret, key, value)\n                    elif unknown == RAISE:\n                        error_store.store_error(\n                            [self.error_messages[\"unknown\"]],\n                            key,\n                            (index if index_errors else None),\n                        )\n        return ret\n\n    def load(self, data, *, many=None, partial=None, unknown=None):\n        \"\"\"Deserialize a data structure to an object defined by this Schema's fields.\n\n        :param dict data: The data to deserialize.\n        :param bool many: Whether to deserialize `data` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to ignore missing fields and not require\n            any fields declared. Propagates down to ``Nested`` fields as well. If\n            its value is an iterable, only missing fields listed in that iterable\n            will be ignored. Use dot delimiters to specify nested fields.\n        :param unknown: Whether to exclude, include, or raise an error for unknown\n            fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.\n            If `None`, the value for `self.unknown` is used.\n        :return: A dict of deserialized data\n        :rtype: dict\n\n        .. versionadded:: 1.0.0\n        .. versionchanged:: 3.0.0b7\n            This method returns the deserialized data rather than a ``(data, errors)`` duple.\n            A :exc:`ValidationError <marshmallow.exceptions.ValidationError>` is raised\n            if invalid data are passed.\n        \"\"\"\n        return self._do_load(\n            data, many=many, partial=partial, unknown=unknown, postprocess=True\n        )\n\n    def loads(self, json_data, *, many=None, partial=None, unknown=None, **kwargs):\n        \"\"\"Same as :meth:`load`, except it takes a JSON string as input.\n\n        :param str json_data: A JSON string of the data to deserialize.\n        :param bool many: Whether to deserialize `obj` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to ignore missing fields and not require\n            any fields declared. Propagates down to ``Nested`` fields as well. If\n            its value is an iterable, only missing fields listed in that iterable\n            will be ignored. Use dot delimiters to specify nested fields.\n        :param unknown: Whether to exclude, include, or raise an error for unknown\n            fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.\n            If `None`, the value for `self.unknown` is used.\n        :return: A dict of deserialized data\n        :rtype: dict\n\n        .. versionadded:: 1.0.0\n        .. versionchanged:: 3.0.0b7\n            This method returns the deserialized data rather than a ``(data, errors)`` duple.\n            A :exc:`ValidationError <marshmallow.exceptions.ValidationError>` is raised\n            if invalid data are passed.\n        \"\"\"\n        data = self.opts.render_module.loads(json_data, **kwargs)\n        return self.load(data, many=many, partial=partial, unknown=unknown)\n\n    def _run_validator(\n        self,\n        validator_func,\n        output,\n        *,\n        original_data,\n        error_store,\n        many,\n        partial,\n        pass_original,\n        index=None\n    ):\n        try:\n            if pass_original:  # Pass original, raw data (before unmarshalling)\n                validator_func(output, original_data, partial=partial, many=many)\n            else:\n                validator_func(output, partial=partial, many=many)\n        except ValidationError as err:\n            error_store.store_error(err.messages, err.field_name, index=index)\n\n    def validate(self, data, *, many=None, partial=None):\n        \"\"\"Validate `data` against the schema, returning a dictionary of\n        validation errors.\n\n        :param dict data: The data to validate.\n        :param bool many: Whether to validate `data` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to ignore missing fields and not require\n            any fields declared. Propagates down to ``Nested`` fields as well. If\n            its value is an iterable, only missing fields listed in that iterable\n            will be ignored. Use dot delimiters to specify nested fields.\n        :return: A dictionary of validation errors.\n        :rtype: dict\n\n        .. versionadded:: 1.1.0\n        \"\"\"\n        try:\n            self._do_load(data, many=many, partial=partial, postprocess=False)\n        except ValidationError as exc:\n            return exc.messages\n        return {}\n\n    ##### Private Helpers #####\n\n    def _do_load(\n        self, data, *, many=None, partial=None, unknown=None, postprocess=True\n    ):\n        \"\"\"Deserialize `data`, returning the deserialized result.\n\n        :param data: The data to deserialize.\n        :param bool many: Whether to deserialize `data` as a collection. If `None`, the\n            value for `self.many` is used.\n        :param bool|tuple partial: Whether to validate required fields. If its\n            value is an iterable, only fields listed in that iterable will be\n            ignored will be allowed missing. If `True`, all fields will be allowed missing.\n            If `None`, the value for `self.partial` is used.\n        :param unknown: Whether to exclude, include, or raise an error for unknown\n            fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.\n            If `None`, the value for `self.unknown` is used.\n        :param bool postprocess: Whether to run post_load methods..\n        :return: A dict of deserialized data\n        :rtype: dict\n        \"\"\"\n        error_store = ErrorStore()\n        errors = {}\n        many = self.many if many is None else bool(many)\n        unknown = unknown or self.unknown\n        if partial is None:\n            partial = self.partial\n        # Run preprocessors\n        if self._has_processors(PRE_LOAD):\n            try:\n                processed_data = self._invoke_load_processors(\n                    PRE_LOAD, data, many=many, original_data=data, partial=partial\n                )\n            except ValidationError as err:\n                errors = err.normalized_messages()\n                result = None\n        else:\n            processed_data = data\n        if not errors:\n            # Deserialize data\n            result = self._deserialize(\n                processed_data,\n                error_store=error_store,\n                many=many,\n                partial=partial,\n                unknown=unknown,\n            )\n            # Run field-level validation\n            self._invoke_field_validators(\n                error_store=error_store, data=result, many=many\n            )\n            # Run schema-level validation\n            if self._has_processors(VALIDATES_SCHEMA):\n                field_errors = bool(error_store.errors)\n                self._invoke_schema_validators(\n                    error_store=error_store,\n                    pass_many=True,\n                    data=result,\n                    original_data=data,\n                    many=many,\n                    partial=partial,\n                    field_errors=field_errors,\n                )\n                self._invoke_schema_validators(\n                    error_store=error_store,\n                    pass_many=False,\n                    data=result,\n                    original_data=data,\n                    many=many,\n                    partial=partial,\n                    field_errors=field_errors,\n                )\n            errors = error_store.errors\n            # Run post processors\n            if not errors and postprocess and self._has_processors(POST_LOAD):\n                try:\n                    result = self._invoke_load_processors(\n                        POST_LOAD,\n                        result,\n                        many=many,\n                        original_data=data,\n                        partial=partial,\n                    )\n                except ValidationError as err:\n                    errors = err.normalized_messages()\n        if errors:\n            exc = ValidationError(errors, data=data, valid_data=result)\n            self.handle_error(exc, data, many=many, partial=partial)\n            raise exc\n\n        return result\n\n    def _normalize_nested_options(self):\n        \"\"\"Apply then flatten nested schema options\"\"\"\n        if self.only is not None:\n            # Apply the only option to nested fields.\n            self.__apply_nested_option(\"only\", self.only, \"intersection\")\n            # Remove the child field names from the only option.\n            self.only = self.set_class([field.split(\".\", 1)[0] for field in self.only])\n        if self.exclude:\n            # Apply the exclude option to nested fields.\n            self.__apply_nested_option(\"exclude\", self.exclude, \"union\")\n            # Remove the parent field names from the exclude option.\n            self.exclude = self.set_class(\n                [field for field in self.exclude if \".\" not in field]\n            )\n\n    def __apply_nested_option(self, option_name, field_names, set_operation):\n        \"\"\"Apply nested options to nested fields\"\"\"\n        # Split nested field names on the first dot.\n        nested_fields = [name.split(\".\", 1) for name in field_names if \".\" in name]\n        # Partition the nested field names by parent field.\n        nested_options = defaultdict(list)\n        for parent, nested_names in nested_fields:\n            nested_options[parent].append(nested_names)\n        # Apply the nested field options.\n        for key, options in iter(nested_options.items()):\n            new_options = self.set_class(options)\n            original_options = getattr(self.declared_fields[key], option_name, ())\n            if original_options:\n                if set_operation == \"union\":\n                    new_options |= self.set_class(original_options)\n                if set_operation == \"intersection\":\n                    new_options &= self.set_class(original_options)\n            setattr(self.declared_fields[key], option_name, new_options)\n\n    def _init_fields(self):\n        \"\"\"Update fields based on schema options.\"\"\"\n        if self.opts.fields:\n            available_field_names = self.set_class(self.opts.fields)\n        else:\n            available_field_names = self.set_class(self.declared_fields.keys())\n            if self.opts.additional:\n                available_field_names |= self.set_class(self.opts.additional)\n\n        invalid_fields = self.set_class()\n\n        if self.only is not None:\n            # Return only fields specified in only option\n            field_names = self.set_class(self.only)\n\n            invalid_fields |= field_names - available_field_names\n        else:\n            field_names = available_field_names\n\n        # If \"exclude\" option or param is specified, remove those fields.\n        if self.exclude:\n            # Note that this isn't available_field_names, since we want to\n            # apply \"only\" for the actual calculation.\n            field_names = field_names - self.exclude\n            invalid_fields |= self.exclude - available_field_names\n\n        if invalid_fields:\n            message = \"Invalid fields for {}: {}.\".format(self, invalid_fields)\n            raise ValueError(message)\n\n        fields_dict = self.dict_class()\n        for field_name in field_names:\n            field_obj = self.declared_fields.get(field_name, ma_fields.Inferred())\n            self._bind_field(field_name, field_obj)\n            fields_dict[field_name] = field_obj\n\n        dump_data_keys = [\n            obj.data_key or name\n            for name, obj in fields_dict.items()\n            if not obj.load_only\n        ]\n        if len(dump_data_keys) != len(set(dump_data_keys)):\n            data_keys_duplicates = {\n                x for x in dump_data_keys if dump_data_keys.count(x) > 1\n            }\n            raise ValueError(\n                \"The data_key argument for one or more fields collides \"\n                \"with another field's name or data_key argument. \"\n                \"Check the following field names and \"\n                \"data_key arguments: {}\".format(list(data_keys_duplicates))\n            )\n\n        load_attributes = [\n            obj.attribute or name\n            for name, obj in fields_dict.items()\n            if not obj.dump_only\n        ]\n        if len(load_attributes) != len(set(load_attributes)):\n            attributes_duplicates = {\n                x for x in load_attributes if load_attributes.count(x) > 1\n            }\n            raise ValueError(\n                \"The attribute argument for one or more fields collides \"\n                \"with another field's name or attribute argument. \"\n                \"Check the following field names and \"\n                \"attribute arguments: {}\".format(list(attributes_duplicates))\n            )\n\n        return fields_dict\n\n    def on_bind_field(self, field_name, field_obj):\n        \"\"\"Hook to modify a field when it is bound to the `Schema`.\n\n        No-op by default.\n        \"\"\"\n        return None\n\n    def _bind_field(self, field_name, field_obj):\n        \"\"\"Bind field to the schema, setting any necessary attributes on the\n        field (e.g. parent and name).\n\n        Also set field load_only and dump_only values if field_name was\n        specified in ``class Meta``.\n        \"\"\"\n        try:\n            if field_name in self.load_only:\n                field_obj.load_only = True\n            if field_name in self.dump_only:\n                field_obj.dump_only = True\n            field_obj._bind_to_schema(field_name, self)\n            self.on_bind_field(field_name, field_obj)\n        except TypeError as error:\n            # field declared as a class, not an instance\n            if isinstance(field_obj, type) and issubclass(field_obj, base.FieldABC):\n                msg = (\n                    'Field for \"{}\" must be declared as a '\n                    \"Field instance, not a class. \"\n                    'Did you mean \"fields.{}()\"?'.format(field_name, field_obj.__name__)\n                )\n                raise TypeError(msg) from error\n\n    @lru_cache(maxsize=8)\n    def _has_processors(self, tag):\n        return self._hooks[(tag, True)] or self._hooks[(tag, False)]\n\n    def _invoke_dump_processors(self, tag, data, *, many, original_data=None):\n        # The pass_many post-dump processors may do things like add an envelope, so\n        # invoke those after invoking the non-pass_many processors which will expect\n        # to get a list of items.\n        data = self._invoke_processors(\n            tag, pass_many=False, data=data, many=many, original_data=original_data\n        )\n        data = self._invoke_processors(\n            tag, pass_many=True, data=data, many=many, original_data=original_data\n        )\n        return data\n\n    def _invoke_load_processors(self, tag, data, *, many, original_data, partial):\n        # This has to invert the order of the dump processors, so run the pass_many\n        # processors first.\n        data = self._invoke_processors(\n            tag,\n            pass_many=True,\n            data=data,\n            many=many,\n            original_data=original_data,\n            partial=partial,\n        )\n        data = self._invoke_processors(\n            tag,\n            pass_many=False,\n            data=data,\n            many=many,\n            original_data=original_data,\n            partial=partial,\n        )\n        return data\n\n    def _invoke_field_validators(self, *, error_store, data, many):\n        for attr_name in self._hooks[VALIDATES]:\n            validator = getattr(self, attr_name)\n            validator_kwargs = validator.__marshmallow_hook__[VALIDATES]\n            field_name = validator_kwargs[\"field_name\"]\n\n            try:\n                field_obj = self.fields[field_name]\n            except KeyError as error:\n                if field_name in self.declared_fields:\n                    continue\n                raise ValueError(\n                    '\"{}\" field does not exist.'.format(field_name)\n                ) from error\n\n            if many:\n                for idx, item in enumerate(data):\n                    try:\n                        value = item[field_obj.attribute or field_name]\n                    except KeyError:\n                        pass\n                    else:\n                        validated_value = self._call_and_store(\n                            getter_func=validator,\n                            data=value,\n                            field_name=field_obj.data_key or field_name,\n                            error_store=error_store,\n                            index=(idx if self.opts.index_errors else None),\n                        )\n                        if validated_value is missing:\n                            data[idx].pop(field_name, None)\n            else:\n                try:\n                    value = data[field_obj.attribute or field_name]\n                except KeyError:\n                    pass\n                else:\n                    validated_value = self._call_and_store(\n                        getter_func=validator,\n                        data=value,\n                        field_name=field_obj.data_key or field_name,\n                        error_store=error_store,\n                    )\n                    if validated_value is missing:\n                        data.pop(field_name, None)\n\n    def _invoke_schema_validators(\n        self,\n        *,\n        error_store,\n        pass_many,\n        data,\n        original_data,\n        many,\n        partial,\n        field_errors=False\n    ):\n        for attr_name in self._hooks[(VALIDATES_SCHEMA, pass_many)]:\n            validator = getattr(self, attr_name)\n            validator_kwargs = validator.__marshmallow_hook__[\n                (VALIDATES_SCHEMA, pass_many)\n            ]\n            if field_errors and validator_kwargs[\"skip_on_field_errors\"]:\n                continue\n            pass_original = validator_kwargs.get(\"pass_original\", False)\n\n            if many and not pass_many:\n                for idx, (item, orig) in enumerate(zip(data, original_data)):\n                    self._run_validator(\n                        validator,\n                        item,\n                        original_data=orig,\n                        error_store=error_store,\n                        many=many,\n                        partial=partial,\n                        index=idx,\n                        pass_original=pass_original,\n                    )\n            else:\n                self._run_validator(\n                    validator,\n                    data,\n                    original_data=original_data,\n                    error_store=error_store,\n                    many=many,\n                    pass_original=pass_original,\n                    partial=partial,\n                )\n\n    def _invoke_processors(\n        self, tag, *, pass_many, data, many, original_data=None, **kwargs\n    ):\n        key = (tag, pass_many)\n        for attr_name in self._hooks[key]:\n            # This will be a bound method.\n            processor = getattr(self, attr_name)\n\n            processor_kwargs = processor.__marshmallow_hook__[key]\n            pass_original = processor_kwargs.get(\"pass_original\", False)\n\n            if pass_many:\n                if pass_original:\n                    data = processor(data, original_data, many=many, **kwargs)\n                else:\n                    data = processor(data, many=many, **kwargs)\n            elif many:\n                if pass_original:\n                    data = [\n                        processor(item, original, many=many, **kwargs)\n                        for item, original in zip(data, original_data)\n                    ]\n                else:\n                    data = [processor(item, many=many, **kwargs) for item in data]\n            else:\n                if pass_original:\n                    data = processor(data, original_data, many=many, **kwargs)\n                else:\n                    data = processor(data, many=many, **kwargs)\n        return data\n\n\nclass Schema(BaseSchema, metaclass=SchemaMeta):\n    __doc__ = BaseSchema.__doc__\n","header":{"file":{"path":"src/marshmallow/schema.py"},"misc_line":null},"index_line":null,"is_binary_file":false,"binary_line":null,"minus_file":{"path":"a/src/marshmallow/schema.py"},"plus_file":{"path":"b/src/marshmallow/schema.py"},"hunks":[{"descriptor":{"old_range":{"start":877,"length":7},"new_range":{"start":877,"length":7},"section":"def _invoke_field_validators(self, unmarshal, data, many):"},"line_group":{"all_lines":[{"content":"                for idx, item in enumerate(data):","type":"context"},{"content":"                    try:","type":"context"},{"content":"                        value = item[field_obj.attribute or field_name]","type":"context"},{"content":"                    except KeyError:","type":"deleted"},{"content":"                    except (KeyError, TypeError):","type":"added"},{"content":"                        pass","type":"context"},{"content":"                    else:","type":"context"},{"content":"                        validated_value = unmarshal.call_and_store(","type":"context"}]},"modified_entities":[],"added_entities":[],"deleted_entities":[]},{"descriptor":{"old_range":{"start":892,"length":7},"new_range":{"start":892,"length":7},"section":"def _invoke_field_validators(self, unmarshal, data, many):"},"line_group":{"all_lines":[{"content":"            else:","type":"context"},{"content":"                try:","type":"context"},{"content":"                    value = data[field_obj.attribute or field_name]","type":"context"},{"content":"                except KeyError:","type":"deleted"},{"content":"                except (KeyError, TypeError):","type":"added"},{"content":"                    pass","type":"context"},{"content":"                else:","type":"context"},{"content":"                    validated_value = unmarshal.call_and_store(","type":"context"},{"content":"","type":"context"}]},"modified_entities":[],"added_entities":[],"deleted_entities":[]}]}],"old_commit_hash":"2be2d83a1a9a6d3d9b85804f3ab545cecc409bb0","new_commit_hash":"a180a25e83203b5f8e55dc685d132a30158272e9","commit_message":"Update changelog","commit_date":"2019-08-21T13:50:03-04:00","metadata":{}}