text: # coding: utf-8
  from __future__ import unicode_literals
  
  import copy
  import warnings
  from collections import OrderedDict
  
  import six
  from django import VERSION
  from django.core.paginator import Paginator
  from django.db.models.fields import FieldDoesNotExist
  from django.template import RequestContext
  from django.template.loader import get_template
  
  from . import columns
  from .config import RequestConfig
  from .rows import BoundRows
  from .utils import (Accessor, AttributeDict, OrderBy, OrderByTuple, Sequence,
                      cached_property, computed_values, segment)
  
  QUERYSET_ACCESSOR_SEPARATOR = '__'
  
  
  class TableData(object):
      """
      Exposes a consistent API for :term:`table data`.
  
      :param  data: iterable containing data for each row
      :type   data: `~django.db.query.QuerySet` or `list` of `dict`
      :param table: `.Table` object
      """
      def __init__(self, data, table):
          self.table = table
          # data may be a QuerySet-like objects with count() and order_by()
          if (hasattr(data, 'count') and callable(data.count) and
              hasattr(data, 'order_by') and callable(data.order_by)):
              self.queryset = data
          # otherwise it must be convertable to a list
          else:
              # do some light validation
              if hasattr(data, '__iter__') or (hasattr(data, '__len__') and hasattr(data, '__getitem__')):
                  self.list = list(data)
              else:
                  raise ValueError(
                      'data must be QuerySet-like (have count and '
                      'order_by) or support list(data) -- %s has '
                      'neither' % type(data).__name__
                  )
  
      def __len__(self):
          if not hasattr(self, "_length"):
              # Use the queryset count() method to get the length, instead of
              # loading all results into memory. This allows, for example,
              # smart paginators that use len() to perform better.
              self._length = (self.queryset.count() if hasattr(self, 'queryset')
                                                    else len(self.list))
          return self._length
  
      @property
      def data(self):
          return self.queryset if hasattr(self, "queryset") else self.list
  
      @property
      def ordering(self):
          """
          Returns the list of order by aliases that are enforcing ordering on the
          data.
  
          If the data is unordered, an empty sequence is returned. If the
          ordering can not be determined, `None` is returned.
  
          This works by inspecting the actual underlying data. As such it's only
          supported for querysets.
          """
          if hasattr(self, "queryset"):
              aliases = {}
              for bound_column in self.table.columns:
                  aliases[bound_column.order_by_alias] = bound_column.order_by
              try:
                  return next(segment(self.queryset.query.order_by, aliases))
              except StopIteration:
                  pass
  
      def order_by(self, aliases):
          """
          Order the data based on order by aliases (prefixed column names) in the
          table.
  
          :param aliases: optionally prefixed names of columns ('-' indicates
                          descending order) in order of significance with
                          regard to data ordering.
          :type  aliases: `~.utils.OrderByTuple`
          """
          accessors = []
          for alias in aliases:
              bound_column = self.table.columns[OrderBy(alias).bare]
              # bound_column.order_by reflects the current ordering applied to
              # the table. As such we need to check the current ordering on the
              # column and use the opposite if it doesn't match the alias prefix.
              if alias[0] != bound_column.order_by_alias[0]:
                  accessors += bound_column.order_by.opposite
              else:
                  accessors += bound_column.order_by
          if hasattr(self, "queryset"):
              translate = lambda accessor: accessor.replace(Accessor.SEPARATOR, QUERYSET_ACCESSOR_SEPARATOR)
              if accessors:
                  self.queryset = self.queryset.order_by(*(translate(a) for a in accessors))
          else:
              self.list.sort(key=OrderByTuple(accessors).key)
  
      def __iter__(self):
          """
          for ... in ... default to using this. There's a bug in Django 1.3
          with indexing into querysets, so this side-steps that problem (as well
          as just being a better way to iterate).
          """
          return iter(self.data)
  
      def __getitem__(self, key):
          """
          Slicing returns a new `.TableData` instance, indexing returns a
          single record.
          """
          return self.data[key]
  
      @cached_property
      def verbose_name(self):
          """
          The full (singular) name for the data.
  
          Queryset data has its model's `~django.db.Model.Meta.verbose_name`
          honored. List data is checked for a ``verbose_name`` attribute, and
          falls back to using ``"item"``.
          """
          if hasattr(self, "queryset"):
              return self.queryset.model._meta.verbose_name
          return getattr(self.list, "verbose_name", "item")
  
      @cached_property
      def verbose_name_plural(self):
          """
          The full (plural) name of the data.
  
          This uses the same approach as `.verbose_name`.
          """
          if hasattr(self, "queryset"):
              return self.queryset.model._meta.verbose_name_plural
          return getattr(self.list, "verbose_name_plural", "items")
  
  
  class DeclarativeColumnsMetaclass(type):
      """
      Metaclass that converts `.Column` objects defined on a class to the
      dictionary `.Table.base_columns`, taking into account parent class
      ``base_columns`` as well.
      """
      def __new__(mcs, name, bases, attrs):
          attrs["_meta"] = opts = TableOptions(attrs.get("Meta", None))
          # extract declared columns
          cols, remainder = [], {}
          for attr_name, attr in attrs.items():
              if isinstance(attr, columns.Column):
                  cols.append((attr_name, attr))
              else:
                  remainder[attr_name] = attr
          attrs = remainder
  
          cols.sort(key=lambda x: x[1].creation_counter)
  
          # If this class is subclassing other tables, add their fields as
          # well. Note that we loop over the bases in *reverse* - this is
          # necessary to preserve the correct order of columns.
          parent_columns = []
          for base in bases[::-1]:
              if hasattr(base, "base_columns"):
                  parent_columns = list(base.base_columns.items()) + parent_columns
          # Start with the parent columns
          attrs["base_columns"] = OrderedDict(parent_columns)
          # Possibly add some generated columns based on a model
          if opts.model:
              extra = OrderedDict()
              # honor Table.Meta.fields, fallback to model._meta.fields
              if opts.fields:
                  # Each item in opts.fields is the name of a model field or a
                  # normal attribute on the model
                  for field_name in opts.fields:
                      try:
                          field = opts.model._meta.get_field(field_name)
                      except FieldDoesNotExist:
                          extra[field_name] = columns.Column()
                      else:
                          extra[field_name] = columns.library.column_for_field(field)
  
              else:
                  for field in opts.model._meta.fields:
                      extra[field.name] = columns.library.column_for_field(field)
              attrs["base_columns"].update(extra)
  
          # Explicit columns override both parent and generated columns
          attrs["base_columns"].update(OrderedDict(cols))
          # Apply any explicit exclude setting
          for exclusion in opts.exclude:
              if exclusion in attrs["base_columns"]:
                  attrs["base_columns"].pop(exclusion)
          # Now reorder the columns based on explicit sequence
          if opts.sequence:
              opts.sequence.expand(attrs["base_columns"].keys())
              # Table's sequence defaults to sequence declared in Meta
              #attrs['_sequence'] = opts.sequence
              attrs["base_columns"] = OrderedDict(((x, attrs["base_columns"][x]) for x in opts.sequence))
  
          # set localize on columns
          for col_name in attrs["base_columns"].keys():
              localize_column = None
              if col_name in opts.localize:
                  localize_column = True
              # unlocalize gets higher precedence
              if col_name in opts.unlocalize:
                  localize_column = False
  
              if localize_column is not None:
                  attrs["base_columns"][col_name].localize = localize_column
  
          return super(DeclarativeColumnsMetaclass, mcs).__new__(mcs, name, bases, attrs)
  
  
  class TableOptions(object):
      """
      Extracts and exposes options for a `.Table` from a `.Table.Meta`
      when the table is defined. See `.Table` for documentation on the impact of
      variables in this class.
  
      :param options: options for a table
      :type  options: `.Table.Meta` on a `.Table`
      """
      # pylint: disable=R0902
      def __init__(self, options=None):
          super(TableOptions, self).__init__()
          self.attrs = AttributeDict(getattr(options, "attrs", {}))
          self.default = getattr(options, "default", "—")
          self.empty_text = getattr(options, "empty_text", None)
          self.fields = getattr(options, "fields", ())
          self.exclude = getattr(options, "exclude", ())
          order_by = getattr(options, "order_by", None)
          if isinstance(order_by, six.string_types):
              order_by = (order_by, )
          self.order_by = OrderByTuple(order_by) if order_by is not None else None
          self.order_by_field = getattr(options, "order_by_field", "sort")
          self.page_field = getattr(options, "page_field", "page")
          self.per_page = getattr(options, "per_page", 25)
          self.per_page_field = getattr(options, "per_page_field", "per_page")
          self.prefix = getattr(options, "prefix", "")
          self.show_header = getattr(options, "show_header", True)
          self.sequence = Sequence(getattr(options, "sequence", ()))
          if hasattr(options, "sortable"):
              warnings.warn("`Table.Meta.sortable` is deprecated, use `orderable` instead",
                            DeprecationWarning)
          self.orderable = self.sortable = getattr(options, "orderable", getattr(options, "sortable", True))
          self.model = getattr(options, "model", None)
          self.template = getattr(options, "template", "django_tables2/table.html")
          self.localize = getattr(options, "localize", ())
          self.unlocalize = getattr(options, "unlocalize", ())
  
  class TableBase(object):
      """
      A representation of a table.
  
  
      .. attribute:: attrs
  
          HTML attributes to add to the ``<table>`` tag.
  
          :type: `dict`
  
          When accessing the attribute, the value is always returned as an
          `.AttributeDict` to allow easily conversion to HTML.
  
  
      .. attribute:: columns
  
          The columns in the table.
  
          :type: `.BoundColumns`
  
  
      .. attribute:: default
  
          Text to render in empty cells (determined by `.Column.empty_values`,
          default `.Table.Meta.default`)
  
          :type: `unicode`
  
  
      .. attribute:: empty_text
  
          Empty text to render when the table has no data. (default
          `.Table.Meta.empty_text`)
  
          :type: `unicode`
  
  
      .. attribute:: exclude
  
          The names of columns that shouldn't be included in the table.
  
          :type: iterable of `unicode`
  
  
      .. attribute:: order_by_field
  
          If not `None`, defines the name of the *order by* querystring field.
  
          :type: `unicode`
  
  
      .. attribute:: page
  
          The current page in the context of pagination.
  
          Added during the call to `.Table.paginate`.
  
  
      .. attribute:: page_field
  
          If not `None`, defines the name of the *current page* querystring
          field.
  
          :type: `unicode`
  
  
      .. attribute:: paginator
  
          The current paginator for the table.
  
          Added during the call to `.Table.paginate`.
  
  
      .. attribute:: per_page_field
  
          If not `None`, defines the name of the *per page* querystring field.
  
          :type: `unicode`
  
  
      .. attribute:: show_header
  
          If `False`, the table will not have a header (`<thead>`), default
          value is `True`
  
          :type: `bool`
  
  
  
      .. attribute:: prefix
  
          A prefix for querystring fields to avoid name-clashes when using
          multiple tables on a single page.
  
          :type: `unicode`
  
  
      .. attribute:: rows
  
          The rows of the table (ignoring pagination).
  
          :type: `.BoundRows`
  
  
      .. attribute:: sequence
  
          The sequence/order of columns the columns (from left to right).
  
          :type: iterable
  
          Items in the sequence must be :term:`column names <column name>`, or
          ``"..."`` (string containing three periods). ``...`` can be used as a
          catch-all for columns that aren't specified.
  
  
      .. attribute:: orderable
  
          Enable/disable column ordering on this table
  
          :type: `bool`
  
  
      .. attribute:: template
  
          The template to render when using ``{% render_table %}`` (default
          ``"django_tables2/table.html"``)
  
          :type: `unicode`
  
      """
      TableDataClass = TableData
  
      def __init__(self, data, order_by=None, orderable=None, empty_text=None,
                   exclude=None, attrs=None, sequence=None, prefix=None,
                   order_by_field=None, page_field=None, per_page_field=None,
                   template=None, sortable=None, default=None, request=None,
                   show_header=None):
          super(TableBase, self).__init__()
          self.exclude = exclude or ()
          self.sequence = sequence
          self.data = self.TableDataClass(data=data, table=self)
          if default is None:
              default = self._meta.default
          self.default = default
          self.rows = BoundRows(data=self.data, table=self)
          self.attrs = AttributeDict(computed_values(attrs if attrs is not None
                                                           else self._meta.attrs))
          self.empty_text = empty_text if empty_text is not None else self._meta.empty_text
          if sortable is not None:
              warnings.warn("`sortable` is deprecated, use `orderable` instead.",
                            DeprecationWarning)
              if orderable is None:
                  orderable = sortable
          self.orderable = orderable
          self.prefix = prefix
          self.order_by_field = order_by_field
          self.page_field = page_field
          self.per_page_field = per_page_field
          self.show_header = show_header
          # Make a copy so that modifying this will not touch the class
          # definition. Note that this is different from forms, where the
          # copy is made available in a ``fields`` attribute.
          self.base_columns = copy.deepcopy(type(self).base_columns)
          # Keep fully expanded ``sequence`` at _sequence so it's easily accessible
          # during render. The priority is as follows:
          # 1. sequence passed in as an argument
          # 2. sequence declared in ``Meta``
          # 3. sequence defaults to '...'
          if sequence is not None:
              self._sequence = Sequence(sequence)
              self._sequence.expand(self.base_columns.keys())
          elif self._meta.sequence:
              self._sequence = self._meta.sequence
          else:
              self._sequence = Sequence(self._meta.fields + ('...',))
              self._sequence.expand(self.base_columns.keys())
          self.columns = columns.BoundColumns(self)
          # `None` value for order_by means no order is specified. This means we
          # `shouldn't touch our data's ordering in any way. *However*
          # `table.order_by = None` means "remove any ordering from the data"
          # (it's equivalent to `table.order_by = ()`).
          if order_by is None and self._meta.order_by is not None:
              order_by = self._meta.order_by
          if order_by is None:
              self._order_by = None
              # If possible inspect the ordering on the data we were given and
              # update the table to reflect that.
              order_by = self.data.ordering
              if order_by is not None:
                  self.order_by = order_by
          else:
              self.order_by = order_by
          self.template = template
          # If a request is passed, configure for request
          if request:
              RequestConfig(request).configure(self)
  
      def as_html(self, request=None):
          """
          Render the table to a simple HTML table, adding `request` to the context.
          """
          template = get_template(self.template)
  
          context = {'table': self}
  
          if request:
              if VERSION < (1, 8):
                  context = RequestContext(request, context)
              else:
                  context['request'] = request
  
          return template.render(context)
  
      @property
      def attrs(self):
          return self._attrs
  
      @attrs.setter
      def attrs(self, value):
          self._attrs = value
  
      @property
      def show_header(self):
          return (self._show_header if self._show_header is not None
                  else self._meta.show_header)
  
      @show_header.setter
      def show_header(self, value):
          self._show_header = value
  
      @property
      def empty_text(self):
          return self._empty_text
  
      @empty_text.setter
      def empty_text(self, value):
          self._empty_text = value
  
      @property
      def order_by(self):
          return self._order_by
  
      @order_by.setter
      def order_by(self, value):
          """
          Order the rows of the table based on columns.
  
          :param value: iterable of order by aliases.
          """
          # collapse empty values to ()
          order_by = () if not value else value
          # accept string
          order_by = order_by.split(',') if isinstance(order_by, six.string_types) else order_by
          valid = []
          # everything's been converted to a iterable, accept iterable!
          for alias in order_by:
              name = OrderBy(alias).bare
              if name in self.columns and self.columns[name].orderable:
                  valid.append(alias)
          self._order_by = OrderByTuple(valid)
          self.data.order_by(self._order_by)
  
      @property
      def order_by_field(self):
          return (self._order_by_field if self._order_by_field is not None
                  else self._meta.order_by_field)
  
      @order_by_field.setter
      def order_by_field(self, value):
          self._order_by_field = value
  
      @property
      def page_field(self):
          return (self._page_field if self._page_field is not None
                  else self._meta.page_field)
  
      @page_field.setter
      def page_field(self, value):
          self._page_field = value
  
      def paginate(self, klass=Paginator, per_page=None, page=1, *args, **kwargs):
          """
          Paginates the table using a paginator and creates a ``page`` property
          containing information for the current page.
  
          :type     klass: Paginator class
          :param    klass: a paginator class to paginate the results
          :type  per_page: `int`
          :param per_page: how many records are displayed on each page
          :type      page: `int`
          :param     page: which page should be displayed.
  
          Extra arguments are passed to the paginator.
  
          Pagination exceptions (`~django.core.paginator.EmptyPage` and
          `~django.core.paginator.PageNotAnInteger`) may be raised from this
          method and should be handled by the caller.
          """
          per_page = per_page or self._meta.per_page
          self.paginator = klass(self.rows, per_page, *args, **kwargs)
          self.page = self.paginator.page(page)
  
      @property
      def per_page_field(self):
          return (self._per_page_field if self._per_page_field is not None
                  else self._meta.per_page_field)
  
      @per_page_field.setter
      def per_page_field(self, value):
          self._per_page_field = value
  
      @property
      def prefix(self):
          return (self._prefix if self._prefix is not None
                  else self._meta.prefix)
  
      @prefix.setter
      def prefix(self, value):
          self._prefix = value
  
      @property
      def prefixed_order_by_field(self):
          return "%s%s" % (self.prefix, self.order_by_field)
  
      @property
      def prefixed_page_field(self):
          return "%s%s" % (self.prefix, self.page_field)
  
      @property
      def prefixed_per_page_field(self):
          return "%s%s" % (self.prefix, self.per_page_field)
  
      @property
      def sequence(self):
          return self._sequence
  
      @sequence.setter
      def sequence(self, value):
          if value:
              value = Sequence(value)
              value.expand(self.base_columns.keys())
          self._sequence = value
  
      @property
      def orderable(self):
          return (self._orderable if self._orderable is not None
                                  else self._meta.orderable)
  
      @orderable.setter
      def orderable(self, value):
          self._orderable = value
  
      @property
      def sortable(self):
          warnings.warn("`sortable` is deprecated, use `orderable` instead.",
                        DeprecationWarning)
          return self.orderable
  
      @sortable.setter
      def sortable(self, value):
          warnings.warn("`sortable` is deprecated, use `orderable` instead.",
                        DeprecationWarning)
          self.orderable = value
  
      @property
      def template(self):
          return (self._template if self._template is not None
                                 else self._meta.template)
  
      @template.setter
      def template(self, value):
          self._template = value
  
  # Python 2/3 compatible way to enable the metaclass
  Table = DeclarativeColumnsMetaclass(str('Table'), (TableBase, ), {})
  