text: #!/usr/bin/env python
  #
  # Copyright 2009 Facebook
  #
  # Licensed under the Apache License, Version 2.0 (the "License"); you may
  # not use this file except in compliance with the License. You may obtain
  # a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  # License for the specific language governing permissions and limitations
  # under the License.
  
  """A command line parsing module that lets modules define their own options.
  
  Each module defines its own options which are added to the global
  option namespace, e.g.::
  
      from tornado.options import define, options
  
      define("mysql_host", default="127.0.0.1:3306", help="Main user DB")
      define("memcache_hosts", default="127.0.0.1:11011", multiple=True,
             help="Main user memcache servers")
  
      def connect():
          db = database.Connection(options.mysql_host)
          ...
  
  The ``main()`` method of your application does not need to be aware of all of
  the options used throughout your program; they are all automatically loaded
  when the modules are loaded.  However, all modules that define options
  must have been imported before the command line is parsed.
  
  Your ``main()`` method can parse the command line or parse a config file with
  either::
  
      tornado.options.parse_command_line()
      # or
      tornado.options.parse_config_file("/etc/server.conf")
  
  .. note:
  
     When using tornado.options.parse_command_line or 
     tornado.options.parse_config_file, the only options that are set are 
     ones that were previously defined with tornado.options.define.
  
  Command line formats are what you would expect (``--myoption=myvalue``).
  Config files are just Python files. Global names become options, e.g.::
  
      myoption = "myvalue"
      myotheroption = "myothervalue"
  
  We support `datetimes <datetime.datetime>`, `timedeltas
  <datetime.timedelta>`, ints, and floats (just pass a ``type`` kwarg to
  `define`). We also accept multi-value options. See the documentation for
  `define()` below.
  
  `tornado.options.options` is a singleton instance of `OptionParser`, and
  the top-level functions in this module (`define`, `parse_command_line`, etc)
  simply call methods on it.  You may create additional `OptionParser`
  instances to define isolated sets of options, such as for subcommands.
  
  .. note::
  
     By default, several options are defined that will configure the
     standard `logging` module when `parse_command_line` or `parse_config_file`
     are called.  If you want Tornado to leave the logging configuration
     alone so you can manage it yourself, either pass ``--logging=none``
     on the command line or do the following to disable it in code::
  
         from tornado.options import options, parse_command_line
         options.logging = None
         parse_command_line()
  
  .. versionchanged:: 4.3
     Dashes and underscores are fully interchangeable in option names;
     options can be defined, set, and read with any mix of the two.
     Dashes are typical for command-line usage while config files require
     underscores.
  """
  
  from __future__ import absolute_import, division, print_function, with_statement
  
  import datetime
  import numbers
  import re
  import sys
  import os
  import textwrap
  
  from tornado.escape import _unicode, native_str
  from tornado.log import define_logging_options
  from tornado import stack_context
  from tornado.util import basestring_type, exec_in
  
  
  class Error(Exception):
      """Exception raised by errors in the options module."""
      pass
  
  
  class OptionParser(object):
      """A collection of options, a dictionary with object-like access.
  
      Normally accessed via static functions in the `tornado.options` module,
      which reference a global instance.
      """
      def __init__(self):
          # we have to use self.__dict__ because we override setattr.
          self.__dict__['_options'] = {}
          self.__dict__['_parse_callbacks'] = []
          self.define("help", type=bool, help="show this help information",
                      callback=self._help_callback)
  
      def _normalize_name(self, name):
          return name.replace('_', '-')
  
      def __getattr__(self, name):
          name = self._normalize_name(name)
          if isinstance(self._options.get(name), _Option):
              return self._options[name].value()
          raise AttributeError("Unrecognized option %r" % name)
  
      def __setattr__(self, name, value):
          name = self._normalize_name(name)
          if isinstance(self._options.get(name), _Option):
              return self._options[name].set(value)
          raise AttributeError("Unrecognized option %r" % name)
  
      def __iter__(self):
          return (opt.name for opt in self._options.values())
  
      def __contains__(self, name):
          name = self._normalize_name(name)
          return name in self._options
  
      def __getitem__(self, name):
          return self.__getattr__(name)
  
      def __setitem__(self, name, value):
          return self.__setattr__(name, value)
  
      def items(self):
          """A sequence of (name, value) pairs.
  
          .. versionadded:: 3.1
          """
          return [(opt.name, opt.value()) for name, opt in self._options.items()]
  
      def groups(self):
          """The set of option-groups created by ``define``.
  
          .. versionadded:: 3.1
          """
          return set(opt.group_name for opt in self._options.values())
  
      def group_dict(self, group):
          """The names and values of options in a group.
  
          Useful for copying options into Application settings::
  
              from tornado.options import define, parse_command_line, options
  
              define('template_path', group='application')
              define('static_path', group='application')
  
              parse_command_line()
  
              application = Application(
                  handlers, **options.group_dict('application'))
  
          .. versionadded:: 3.1
          """
          return dict(
              (opt.name, opt.value()) for name, opt in self._options.items()
              if not group or group == opt.group_name)
  
      def as_dict(self):
          """The names and values of all options.
  
          .. versionadded:: 3.1
          """
          return dict(
              (opt.name, opt.value()) for name, opt in self._options.items())
  
      def define(self, name, default=None, type=None, help=None, metavar=None,
                 multiple=False, group=None, callback=None):
          """Defines a new command line option.
  
          If ``type`` is given (one of str, float, int, datetime, or timedelta)
          or can be inferred from the ``default``, we parse the command line
          arguments based on the given type. If ``multiple`` is True, we accept
          comma-separated values, and the option value is always a list.
  
          For multi-value integers, we also accept the syntax ``x:y``, which
          turns into ``range(x, y)`` - very useful for long integer ranges.
  
          ``help`` and ``metavar`` are used to construct the
          automatically generated command line help string. The help
          message is formatted like::
  
             --name=METAVAR      help string
  
          ``group`` is used to group the defined options in logical
          groups. By default, command line options are grouped by the
          file in which they are defined.
  
          Command line option names must be unique globally. They can be parsed
          from the command line with `parse_command_line` or parsed from a
          config file with `parse_config_file`.
  
          If a ``callback`` is given, it will be run with the new value whenever
          the option is changed.  This can be used to combine command-line
          and file-based options::
  
              define("config", type=str, help="path to config file",
                     callback=lambda path: parse_config_file(path, final=False))
  
          With this definition, options in the file specified by ``--config`` will
          override options set earlier on the command line, but can be overridden
          by later flags.
          """
          if name in self._options:
              raise Error("Option %r already defined in %s" %
                          (name, self._options[name].file_name))
          frame = sys._getframe(0)
          options_file = frame.f_code.co_filename
  
          # Can be called directly, or through top level define() fn, in which
          # case, step up above that frame to look for real caller.
          if (frame.f_back.f_code.co_filename == options_file and
                  frame.f_back.f_code.co_name == 'define'):
              frame = frame.f_back
  
          file_name = frame.f_back.f_code.co_filename
          if file_name == options_file:
              file_name = ""
          if type is None:
              if not multiple and default is not None:
                  type = default.__class__
              else:
                  type = str
          if group:
              group_name = group
          else:
              group_name = file_name
          normalized = self._normalize_name(name)
          option = _Option(name, file_name=file_name,
                           default=default, type=type, help=help,
                           metavar=metavar, multiple=multiple,
                           group_name=group_name,
                           callback=callback)
          self._options[normalized] = option
  
      def parse_command_line(self, args=None, final=True):
          """Parses all options given on the command line (defaults to
          `sys.argv`).
  
          Note that ``args[0]`` is ignored since it is the program name
          in `sys.argv`.
  
          We return a list of all arguments that are not parsed as options.
  
          If ``final`` is ``False``, parse callbacks will not be run.
          This is useful for applications that wish to combine configurations
          from multiple sources.
          """
          if args is None:
              args = sys.argv
          remaining = []
          for i in range(1, len(args)):
              # All things after the last option are command line arguments
              if not args[i].startswith("-"):
                  remaining = args[i:]
                  break
              if args[i] == "--":
                  remaining = args[i + 1:]
                  break
              arg = args[i].lstrip("-")
              name, equals, value = arg.partition("=")
              name = self._normalize_name(name)
              if name not in self._options:
                  self.print_help()
                  raise Error('Unrecognized command line option: %r' % name)
              option = self._options[name]
              if not equals:
                  if option.type == bool:
                      value = "true"
                  else:
                      raise Error('Option %r requires a value' % name)
              option.parse(value)
  
          if final:
              self.run_parse_callbacks()
  
          return remaining
  
      def parse_config_file(self, path, final=True):
          """Parses and loads the Python config file at the given path.
  
          If ``final`` is ``False``, parse callbacks will not be run.
          This is useful for applications that wish to combine configurations
          from multiple sources.
  
          .. versionchanged:: 4.1
             Config files are now always interpreted as utf-8 instead of
             the system default encoding.
          """
          config = {}
          with open(path, 'rb') as f:
              exec_in(native_str(f.read()), config, config)
          for name in config:
              normalized = self._normalize_name(name)
              if normalized in self._options:
                  self._options[normalized].set(config[name])
  
          if final:
              self.run_parse_callbacks()
  
      def print_help(self, file=None):
          """Prints all the command line options to stderr (or another file)."""
          if file is None:
              file = sys.stderr
          print("Usage: %s [OPTIONS]" % sys.argv[0], file=file)
          print("\nOptions:\n", file=file)
          by_group = {}
          for option in self._options.values():
              by_group.setdefault(option.group_name, []).append(option)
  
          for filename, o in sorted(by_group.items()):
              if filename:
                  print("\n%s options:\n" % os.path.normpath(filename), file=file)
              o.sort(key=lambda option: option.name)
              for option in o:
                  # Always print names with dashes in a CLI context.
                  prefix = self._normalize_name(option.name)
                  if option.metavar:
                      prefix += "=" + option.metavar
                  description = option.help or ""
                  if option.default is not None and option.default != '':
                      description += " (default %s)" % option.default
                  lines = textwrap.wrap(description, 79 - 35)
                  if len(prefix) > 30 or len(lines) == 0:
                      lines.insert(0, '')
                  print("  --%-30s %s" % (prefix, lines[0]), file=file)
                  for line in lines[1:]:
                      print("%-34s %s" % (' ', line), file=file)
          print(file=file)
  
      def _help_callback(self, value):
          if value:
              self.print_help()
              sys.exit(0)
  
      def add_parse_callback(self, callback):
          """Adds a parse callback, to be invoked when option parsing is done."""
          self._parse_callbacks.append(stack_context.wrap(callback))
  
      def run_parse_callbacks(self):
          for callback in self._parse_callbacks:
              callback()
  
      def mockable(self):
          """Returns a wrapper around self that is compatible with
          `mock.patch <unittest.mock.patch>`.
  
          The `mock.patch <unittest.mock.patch>` function (included in
          the standard library `unittest.mock` package since Python 3.3,
          or in the third-party ``mock`` package for older versions of
          Python) is incompatible with objects like ``options`` that
          override ``__getattr__`` and ``__setattr__``.  This function
          returns an object that can be used with `mock.patch.object
          <unittest.mock.patch.object>` to modify option values::
  
              with mock.patch.object(options.mockable(), 'name', value):
                  assert options.name == value
          """
          return _Mockable(self)
  
  
  class _Mockable(object):
      """`mock.patch` compatible wrapper for `OptionParser`.
  
      As of ``mock`` version 1.0.1, when an object uses ``__getattr__``
      hooks instead of ``__dict__``, ``patch.__exit__`` tries to delete
      the attribute it set instead of setting a new one (assuming that
      the object does not catpure ``__setattr__``, so the patch
      created a new attribute in ``__dict__``).
  
      _Mockable's getattr and setattr pass through to the underlying
      OptionParser, and delattr undoes the effect of a previous setattr.
      """
      def __init__(self, options):
          # Modify __dict__ directly to bypass __setattr__
          self.__dict__['_options'] = options
          self.__dict__['_originals'] = {}
  
      def __getattr__(self, name):
          return getattr(self._options, name)
  
      def __setattr__(self, name, value):
          assert name not in self._originals, "don't reuse mockable objects"
          self._originals[name] = getattr(self._options, name)
          setattr(self._options, name, value)
  
      def __delattr__(self, name):
          setattr(self._options, name, self._originals.pop(name))
  
  
  class _Option(object):
      UNSET = object()
  
      def __init__(self, name, default=None, type=basestring_type, help=None,
                   metavar=None, multiple=False, file_name=None, group_name=None,
                   callback=None):
          if default is None and multiple:
              default = []
          self.name = name
          self.type = type
          self.help = help
          self.metavar = metavar
          self.multiple = multiple
          self.file_name = file_name
          self.group_name = group_name
          self.callback = callback
          self.default = default
          self._value = _Option.UNSET
  
      def value(self):
          return self.default if self._value is _Option.UNSET else self._value
  
      def parse(self, value):
          _parse = {
              datetime.datetime: self._parse_datetime,
              datetime.timedelta: self._parse_timedelta,
              bool: self._parse_bool,
              basestring_type: self._parse_string,
          }.get(self.type, self.type)
          if self.multiple:
              self._value = []
              for part in value.split(","):
                  if issubclass(self.type, numbers.Integral):
                      # allow ranges of the form X:Y (inclusive at both ends)
                      lo, _, hi = part.partition(":")
                      lo = _parse(lo)
                      hi = _parse(hi) if hi else lo
                      self._value.extend(range(lo, hi + 1))
                  else:
                      self._value.append(_parse(part))
          else:
              self._value = _parse(value)
          if self.callback is not None:
              self.callback(self._value)
          return self.value()
  
      def set(self, value):
          if self.multiple:
              if not isinstance(value, list):
                  raise Error("Option %r is required to be a list of %s" %
                              (self.name, self.type.__name__))
              for item in value:
                  if item is not None and not isinstance(item, self.type):
                      raise Error("Option %r is required to be a list of %s" %
                                  (self.name, self.type.__name__))
          else:
              if value is not None and not isinstance(value, self.type):
                  raise Error("Option %r is required to be a %s (%s given)" %
                              (self.name, self.type.__name__, type(value)))
          self._value = value
          if self.callback is not None:
              self.callback(self._value)
  
      # Supported date/time formats in our options
      _DATETIME_FORMATS = [
          "%a %b %d %H:%M:%S %Y",
          "%Y-%m-%d %H:%M:%S",
          "%Y-%m-%d %H:%M",
          "%Y-%m-%dT%H:%M",
          "%Y%m%d %H:%M:%S",
          "%Y%m%d %H:%M",
          "%Y-%m-%d",
          "%Y%m%d",
          "%H:%M:%S",
          "%H:%M",
      ]
  
      def _parse_datetime(self, value):
          for format in self._DATETIME_FORMATS:
              try:
                  return datetime.datetime.strptime(value, format)
              except ValueError:
                  pass
          raise Error('Unrecognized date/time format: %r' % value)
  
      _TIMEDELTA_ABBREV_DICT = {
          'h': 'hours',
          'm': 'minutes',
          'min': 'minutes',
          's': 'seconds',
          'sec': 'seconds',
          'ms': 'milliseconds',
          'us': 'microseconds',
          'd': 'days',
          'w': 'weeks',
      }
  
      _FLOAT_PATTERN = r'[-+]?(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][-+]?\d+)?'
  
      _TIMEDELTA_PATTERN = re.compile(
          r'\s*(%s)\s*(\w*)\s*' % _FLOAT_PATTERN, re.IGNORECASE)
  
      def _parse_timedelta(self, value):
          try:
              sum = datetime.timedelta()
              start = 0
              while start < len(value):
                  m = self._TIMEDELTA_PATTERN.match(value, start)
                  if not m:
                      raise Exception()
                  num = float(m.group(1))
                  units = m.group(2) or 'seconds'
                  units = self._TIMEDELTA_ABBREV_DICT.get(units, units)
                  sum += datetime.timedelta(**{units: num})
                  start = m.end()
              return sum
          except Exception:
              raise
  
      def _parse_bool(self, value):
          return value.lower() not in ("false", "0", "f")
  
      def _parse_string(self, value):
          return _unicode(value)
  
  
  options = OptionParser()
  """Global options object.
  
  All defined options are available as attributes on this object.
  """
  
  
  def define(name, default=None, type=None, help=None, metavar=None,
             multiple=False, group=None, callback=None):
      """Defines an option in the global namespace.
  
      See `OptionParser.define`.
      """
      return options.define(name, default=default, type=type, help=help,
                            metavar=metavar, multiple=multiple, group=group,
                            callback=callback)
  
  
  def parse_command_line(args=None, final=True):
      """Parses global options from the command line.
  
      See `OptionParser.parse_command_line`.
      """
      return options.parse_command_line(args, final=final)
  
  
  def parse_config_file(path, final=True):
      """Parses global options from a config file.
  
      See `OptionParser.parse_config_file`.
      """
      return options.parse_config_file(path, final=final)
  
  
  def print_help(file=None):
      """Prints all the command line options to stderr (or another file).
  
      See `OptionParser.print_help`.
      """
      return options.print_help(file)
  
  
  def add_parse_callback(callback):
      """Adds a parse callback, to be invoked when option parsing is done.
  
      See `OptionParser.add_parse_callback`
      """
      options.add_parse_callback(callback)
  
  
  # Default options
  define_logging_options(options)
  