827 lines
24 KiB
Python
827 lines
24 KiB
Python
# -*- coding: utf-8 -*-
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"""
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requests.utils
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~~~~~~~~~~~~~~
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This module provides utility functions that are used within Requests
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that are also useful for external consumption.
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"""
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import cgi
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import codecs
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import collections
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import io
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import os
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import re
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import socket
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import struct
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import warnings
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from . import __version__
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from . import certs
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# to_native_string is unused here, but imported here for backwards compatibility
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from ._internal_utils import to_native_string
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from .compat import parse_http_list as _parse_list_header
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from .compat import (
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quote, urlparse, bytes, str, OrderedDict, unquote, getproxies,
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proxy_bypass, urlunparse, basestring, integer_types)
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from .cookies import RequestsCookieJar, cookiejar_from_dict
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from .structures import CaseInsensitiveDict
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from .exceptions import (
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InvalidURL, InvalidHeader, FileModeWarning, UnrewindableBodyError)
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_hush_pyflakes = (RequestsCookieJar,)
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NETRC_FILES = ('.netrc', '_netrc')
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DEFAULT_CA_BUNDLE_PATH = certs.where()
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def dict_to_sequence(d):
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"""Returns an internal sequence dictionary update."""
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if hasattr(d, 'items'):
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d = d.items()
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return d
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def super_len(o):
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total_length = None
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current_position = 0
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if hasattr(o, '__len__'):
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total_length = len(o)
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elif hasattr(o, 'len'):
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total_length = o.len
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elif hasattr(o, 'fileno'):
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try:
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fileno = o.fileno()
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except io.UnsupportedOperation:
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pass
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else:
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total_length = os.fstat(fileno).st_size
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# Having used fstat to determine the file length, we need to
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# confirm that this file was opened up in binary mode.
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if 'b' not in o.mode:
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warnings.warn((
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"Requests has determined the content-length for this "
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"request using the binary size of the file: however, the "
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"file has been opened in text mode (i.e. without the 'b' "
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"flag in the mode). This may lead to an incorrect "
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"content-length. In Requests 3.0, support will be removed "
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"for files in text mode."),
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FileModeWarning
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)
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if hasattr(o, 'tell'):
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try:
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current_position = o.tell()
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except (OSError, IOError):
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# This can happen in some weird situations, such as when the file
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# is actually a special file descriptor like stdin. In this
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# instance, we don't know what the length is, so set it to zero and
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# let requests chunk it instead.
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if total_length is not None:
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current_position = total_length
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else:
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if hasattr(o, 'seek') and total_length is None:
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# StringIO and BytesIO have seek but no useable fileno
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# seek to end of file
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o.seek(0, 2)
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total_length = o.tell()
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# seek back to current position to support
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# partially read file-like objects
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o.seek(current_position or 0)
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if total_length is None:
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total_length = 0
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return max(0, total_length - current_position)
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def get_netrc_auth(url, raise_errors=False):
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"""Returns the Requests tuple auth for a given url from netrc."""
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try:
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from netrc import netrc, NetrcParseError
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netrc_path = None
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for f in NETRC_FILES:
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try:
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loc = os.path.expanduser('~/{0}'.format(f))
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except KeyError:
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# os.path.expanduser can fail when $HOME is undefined and
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# getpwuid fails. See http://bugs.python.org/issue20164 &
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# https://github.com/kennethreitz/requests/issues/1846
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return
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if os.path.exists(loc):
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netrc_path = loc
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break
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# Abort early if there isn't one.
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if netrc_path is None:
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return
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ri = urlparse(url)
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# Strip port numbers from netloc. This weird `if...encode`` dance is
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# used for Python 3.2, which doesn't support unicode literals.
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splitstr = b':'
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if isinstance(url, str):
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splitstr = splitstr.decode('ascii')
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host = ri.netloc.split(splitstr)[0]
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try:
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_netrc = netrc(netrc_path).authenticators(host)
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if _netrc:
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# Return with login / password
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login_i = (0 if _netrc[0] else 1)
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return (_netrc[login_i], _netrc[2])
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except (NetrcParseError, IOError):
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# If there was a parsing error or a permissions issue reading the file,
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# we'll just skip netrc auth unless explicitly asked to raise errors.
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if raise_errors:
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raise
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# AppEngine hackiness.
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except (ImportError, AttributeError):
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pass
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def guess_filename(obj):
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"""Tries to guess the filename of the given object."""
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name = getattr(obj, 'name', None)
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if (name and isinstance(name, basestring) and name[0] != '<' and
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name[-1] != '>'):
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return os.path.basename(name)
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def from_key_val_list(value):
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"""Take an object and test to see if it can be represented as a
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dictionary. Unless it can not be represented as such, return an
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OrderedDict, e.g.,
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::
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>>> from_key_val_list([('key', 'val')])
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OrderedDict([('key', 'val')])
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>>> from_key_val_list('string')
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ValueError: need more than 1 value to unpack
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>>> from_key_val_list({'key': 'val'})
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OrderedDict([('key', 'val')])
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:rtype: OrderedDict
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"""
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if value is None:
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return None
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if isinstance(value, (str, bytes, bool, int)):
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raise ValueError('cannot encode objects that are not 2-tuples')
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return OrderedDict(value)
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def to_key_val_list(value):
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"""Take an object and test to see if it can be represented as a
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dictionary. If it can be, return a list of tuples, e.g.,
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::
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>>> to_key_val_list([('key', 'val')])
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[('key', 'val')]
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>>> to_key_val_list({'key': 'val'})
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[('key', 'val')]
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>>> to_key_val_list('string')
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ValueError: cannot encode objects that are not 2-tuples.
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:rtype: list
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"""
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if value is None:
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return None
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if isinstance(value, (str, bytes, bool, int)):
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raise ValueError('cannot encode objects that are not 2-tuples')
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if isinstance(value, collections.Mapping):
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value = value.items()
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return list(value)
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# From mitsuhiko/werkzeug (used with permission).
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def parse_list_header(value):
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"""Parse lists as described by RFC 2068 Section 2.
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In particular, parse comma-separated lists where the elements of
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the list may include quoted-strings. A quoted-string could
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contain a comma. A non-quoted string could have quotes in the
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middle. Quotes are removed automatically after parsing.
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It basically works like :func:`parse_set_header` just that items
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may appear multiple times and case sensitivity is preserved.
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The return value is a standard :class:`list`:
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>>> parse_list_header('token, "quoted value"')
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['token', 'quoted value']
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To create a header from the :class:`list` again, use the
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:func:`dump_header` function.
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:param value: a string with a list header.
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:return: :class:`list`
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:rtype: list
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"""
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result = []
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for item in _parse_list_header(value):
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if item[:1] == item[-1:] == '"':
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item = unquote_header_value(item[1:-1])
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result.append(item)
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return result
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# From mitsuhiko/werkzeug (used with permission).
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def parse_dict_header(value):
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"""Parse lists of key, value pairs as described by RFC 2068 Section 2 and
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convert them into a python dict:
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>>> d = parse_dict_header('foo="is a fish", bar="as well"')
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>>> type(d) is dict
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True
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>>> sorted(d.items())
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[('bar', 'as well'), ('foo', 'is a fish')]
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If there is no value for a key it will be `None`:
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>>> parse_dict_header('key_without_value')
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{'key_without_value': None}
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To create a header from the :class:`dict` again, use the
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:func:`dump_header` function.
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:param value: a string with a dict header.
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:return: :class:`dict`
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:rtype: dict
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"""
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result = {}
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for item in _parse_list_header(value):
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if '=' not in item:
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result[item] = None
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continue
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name, value = item.split('=', 1)
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if value[:1] == value[-1:] == '"':
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value = unquote_header_value(value[1:-1])
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result[name] = value
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return result
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# From mitsuhiko/werkzeug (used with permission).
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def unquote_header_value(value, is_filename=False):
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r"""Unquotes a header value. (Reversal of :func:`quote_header_value`).
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This does not use the real unquoting but what browsers are actually
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using for quoting.
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:param value: the header value to unquote.
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:rtype: str
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"""
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if value and value[0] == value[-1] == '"':
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# this is not the real unquoting, but fixing this so that the
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# RFC is met will result in bugs with internet explorer and
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# probably some other browsers as well. IE for example is
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# uploading files with "C:\foo\bar.txt" as filename
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value = value[1:-1]
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# if this is a filename and the starting characters look like
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# a UNC path, then just return the value without quotes. Using the
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# replace sequence below on a UNC path has the effect of turning
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# the leading double slash into a single slash and then
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# _fix_ie_filename() doesn't work correctly. See #458.
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if not is_filename or value[:2] != '\\\\':
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return value.replace('\\\\', '\\').replace('\\"', '"')
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return value
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def dict_from_cookiejar(cj):
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"""Returns a key/value dictionary from a CookieJar.
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:param cj: CookieJar object to extract cookies from.
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:rtype: dict
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"""
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cookie_dict = {}
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for cookie in cj:
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cookie_dict[cookie.name] = cookie.value
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return cookie_dict
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def add_dict_to_cookiejar(cj, cookie_dict):
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"""Returns a CookieJar from a key/value dictionary.
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:param cj: CookieJar to insert cookies into.
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:param cookie_dict: Dict of key/values to insert into CookieJar.
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:rtype: CookieJar
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"""
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return cookiejar_from_dict(cookie_dict, cj)
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def get_encodings_from_content(content):
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"""Returns encodings from given content string.
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:param content: bytestring to extract encodings from.
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"""
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warnings.warn((
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'In requests 3.0, get_encodings_from_content will be removed. For '
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'more information, please see the discussion on issue #2266. (This'
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' warning should only appear once.)'),
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DeprecationWarning)
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charset_re = re.compile(r'<meta.*?charset=["\']*(.+?)["\'>]', flags=re.I)
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pragma_re = re.compile(r'<meta.*?content=["\']*;?charset=(.+?)["\'>]', flags=re.I)
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xml_re = re.compile(r'^<\?xml.*?encoding=["\']*(.+?)["\'>]')
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return (charset_re.findall(content) +
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pragma_re.findall(content) +
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xml_re.findall(content))
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def get_encoding_from_headers(headers):
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"""Returns encodings from given HTTP Header Dict.
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:param headers: dictionary to extract encoding from.
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:rtype: str
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"""
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content_type = headers.get('content-type')
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if not content_type:
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return None
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content_type, params = cgi.parse_header(content_type)
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if 'charset' in params:
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return params['charset'].strip("'\"")
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if 'text' in content_type:
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return 'ISO-8859-1'
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def stream_decode_response_unicode(iterator, r):
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"""Stream decodes a iterator."""
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if r.encoding is None:
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for item in iterator:
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yield item
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return
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decoder = codecs.getincrementaldecoder(r.encoding)(errors='replace')
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for chunk in iterator:
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rv = decoder.decode(chunk)
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if rv:
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yield rv
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rv = decoder.decode(b'', final=True)
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if rv:
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yield rv
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def iter_slices(string, slice_length):
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"""Iterate over slices of a string."""
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pos = 0
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if slice_length is None or slice_length <= 0:
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slice_length = len(string)
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while pos < len(string):
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yield string[pos:pos + slice_length]
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pos += slice_length
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def get_unicode_from_response(r):
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"""Returns the requested content back in unicode.
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:param r: Response object to get unicode content from.
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Tried:
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1. charset from content-type
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2. fall back and replace all unicode characters
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:rtype: str
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"""
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warnings.warn((
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'In requests 3.0, get_unicode_from_response will be removed. For '
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'more information, please see the discussion on issue #2266. (This'
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' warning should only appear once.)'),
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DeprecationWarning)
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tried_encodings = []
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# Try charset from content-type
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encoding = get_encoding_from_headers(r.headers)
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if encoding:
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try:
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return str(r.content, encoding)
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except UnicodeError:
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tried_encodings.append(encoding)
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# Fall back:
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try:
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return str(r.content, encoding, errors='replace')
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except TypeError:
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return r.content
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|
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# The unreserved URI characters (RFC 3986)
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UNRESERVED_SET = frozenset(
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"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
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+ "0123456789-._~")
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|
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def unquote_unreserved(uri):
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"""Un-escape any percent-escape sequences in a URI that are unreserved
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characters. This leaves all reserved, illegal and non-ASCII bytes encoded.
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:rtype: str
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"""
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parts = uri.split('%')
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for i in range(1, len(parts)):
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h = parts[i][0:2]
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if len(h) == 2 and h.isalnum():
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try:
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c = chr(int(h, 16))
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except ValueError:
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raise InvalidURL("Invalid percent-escape sequence: '%s'" % h)
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|
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if c in UNRESERVED_SET:
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parts[i] = c + parts[i][2:]
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else:
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parts[i] = '%' + parts[i]
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else:
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parts[i] = '%' + parts[i]
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return ''.join(parts)
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|
|
|
|
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def requote_uri(uri):
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"""Re-quote the given URI.
|
|
|
|
This function passes the given URI through an unquote/quote cycle to
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ensure that it is fully and consistently quoted.
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:rtype: str
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"""
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safe_with_percent = "!#$%&'()*+,/:;=?@[]~"
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safe_without_percent = "!#$&'()*+,/:;=?@[]~"
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try:
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# Unquote only the unreserved characters
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# Then quote only illegal characters (do not quote reserved,
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# unreserved, or '%')
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return quote(unquote_unreserved(uri), safe=safe_with_percent)
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except InvalidURL:
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# We couldn't unquote the given URI, so let's try quoting it, but
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# there may be unquoted '%'s in the URI. We need to make sure they're
|
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# properly quoted so they do not cause issues elsewhere.
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return quote(uri, safe=safe_without_percent)
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|
|
|
|
|
def address_in_network(ip, net):
|
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"""This function allows you to check if on IP belongs to a network subnet
|
|
|
|
Example: returns True if ip = 192.168.1.1 and net = 192.168.1.0/24
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returns False if ip = 192.168.1.1 and net = 192.168.100.0/24
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:rtype: bool
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"""
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ipaddr = struct.unpack('=L', socket.inet_aton(ip))[0]
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netaddr, bits = net.split('/')
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netmask = struct.unpack('=L', socket.inet_aton(dotted_netmask(int(bits))))[0]
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network = struct.unpack('=L', socket.inet_aton(netaddr))[0] & netmask
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return (ipaddr & netmask) == (network & netmask)
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|
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def dotted_netmask(mask):
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"""Converts mask from /xx format to xxx.xxx.xxx.xxx
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Example: if mask is 24 function returns 255.255.255.0
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:rtype: str
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"""
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bits = 0xffffffff ^ (1 << 32 - mask) - 1
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return socket.inet_ntoa(struct.pack('>I', bits))
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def is_ipv4_address(string_ip):
|
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"""
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:rtype: bool
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|
"""
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try:
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socket.inet_aton(string_ip)
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except socket.error:
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return False
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return True
|
|
|
|
|
|
def is_valid_cidr(string_network):
|
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"""
|
|
Very simple check of the cidr format in no_proxy variable.
|
|
|
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:rtype: bool
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"""
|
|
if string_network.count('/') == 1:
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try:
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mask = int(string_network.split('/')[1])
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except ValueError:
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return False
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|
|
|
if mask < 1 or mask > 32:
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return False
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|
|
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try:
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socket.inet_aton(string_network.split('/')[0])
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except socket.error:
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return False
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else:
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return False
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return True
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|
|
|
|
def should_bypass_proxies(url):
|
|
"""
|
|
Returns whether we should bypass proxies or not.
|
|
|
|
:rtype: bool
|
|
"""
|
|
get_proxy = lambda k: os.environ.get(k) or os.environ.get(k.upper())
|
|
|
|
# First check whether no_proxy is defined. If it is, check that the URL
|
|
# we're getting isn't in the no_proxy list.
|
|
no_proxy = get_proxy('no_proxy')
|
|
netloc = urlparse(url).netloc
|
|
|
|
if no_proxy:
|
|
# We need to check whether we match here. We need to see if we match
|
|
# the end of the netloc, both with and without the port.
|
|
no_proxy = (
|
|
host for host in no_proxy.replace(' ', '').split(',') if host
|
|
)
|
|
|
|
ip = netloc.split(':')[0]
|
|
if is_ipv4_address(ip):
|
|
for proxy_ip in no_proxy:
|
|
if is_valid_cidr(proxy_ip):
|
|
if address_in_network(ip, proxy_ip):
|
|
return True
|
|
elif ip == proxy_ip:
|
|
# If no_proxy ip was defined in plain IP notation instead of cidr notation &
|
|
# matches the IP of the index
|
|
return True
|
|
else:
|
|
for host in no_proxy:
|
|
if netloc.endswith(host) or netloc.split(':')[0].endswith(host):
|
|
# The URL does match something in no_proxy, so we don't want
|
|
# to apply the proxies on this URL.
|
|
return True
|
|
|
|
# If the system proxy settings indicate that this URL should be bypassed,
|
|
# don't proxy.
|
|
# The proxy_bypass function is incredibly buggy on OS X in early versions
|
|
# of Python 2.6, so allow this call to fail. Only catch the specific
|
|
# exceptions we've seen, though: this call failing in other ways can reveal
|
|
# legitimate problems.
|
|
try:
|
|
bypass = proxy_bypass(netloc)
|
|
except (TypeError, socket.gaierror):
|
|
bypass = False
|
|
|
|
if bypass:
|
|
return True
|
|
|
|
return False
|
|
|
|
|
|
def get_environ_proxies(url):
|
|
"""
|
|
Return a dict of environment proxies.
|
|
|
|
:rtype: dict
|
|
"""
|
|
if should_bypass_proxies(url):
|
|
return {}
|
|
else:
|
|
return getproxies()
|
|
|
|
|
|
def select_proxy(url, proxies):
|
|
"""Select a proxy for the url, if applicable.
|
|
|
|
:param url: The url being for the request
|
|
:param proxies: A dictionary of schemes or schemes and hosts to proxy URLs
|
|
"""
|
|
proxies = proxies or {}
|
|
urlparts = urlparse(url)
|
|
if urlparts.hostname is None:
|
|
return proxies.get(urlparts.scheme, proxies.get('all'))
|
|
|
|
proxy_keys = [
|
|
urlparts.scheme + '://' + urlparts.hostname,
|
|
urlparts.scheme,
|
|
'all://' + urlparts.hostname,
|
|
'all',
|
|
]
|
|
proxy = None
|
|
for proxy_key in proxy_keys:
|
|
if proxy_key in proxies:
|
|
proxy = proxies[proxy_key]
|
|
break
|
|
|
|
return proxy
|
|
|
|
|
|
def default_user_agent(name="python-requests"):
|
|
"""
|
|
Return a string representing the default user agent.
|
|
|
|
:rtype: str
|
|
"""
|
|
return '%s/%s' % (name, __version__)
|
|
|
|
|
|
def default_headers():
|
|
"""
|
|
:rtype: requests.structures.CaseInsensitiveDict
|
|
"""
|
|
return CaseInsensitiveDict({
|
|
'User-Agent': default_user_agent(),
|
|
'Accept-Encoding': ', '.join(('gzip', 'deflate')),
|
|
'Accept': '*/*',
|
|
'Connection': 'keep-alive',
|
|
})
|
|
|
|
|
|
def parse_header_links(value):
|
|
"""Return a dict of parsed link headers proxies.
|
|
|
|
i.e. Link: <http:/.../front.jpeg>; rel=front; type="image/jpeg",<http://.../back.jpeg>; rel=back;type="image/jpeg"
|
|
|
|
:rtype: list
|
|
"""
|
|
|
|
links = []
|
|
|
|
replace_chars = ' \'"'
|
|
|
|
for val in re.split(', *<', value):
|
|
try:
|
|
url, params = val.split(';', 1)
|
|
except ValueError:
|
|
url, params = val, ''
|
|
|
|
link = {'url': url.strip('<> \'"')}
|
|
|
|
for param in params.split(';'):
|
|
try:
|
|
key, value = param.split('=')
|
|
except ValueError:
|
|
break
|
|
|
|
link[key.strip(replace_chars)] = value.strip(replace_chars)
|
|
|
|
links.append(link)
|
|
|
|
return links
|
|
|
|
|
|
# Null bytes; no need to recreate these on each call to guess_json_utf
|
|
_null = '\x00'.encode('ascii') # encoding to ASCII for Python 3
|
|
_null2 = _null * 2
|
|
_null3 = _null * 3
|
|
|
|
|
|
def guess_json_utf(data):
|
|
"""
|
|
:rtype: str
|
|
"""
|
|
# JSON always starts with two ASCII characters, so detection is as
|
|
# easy as counting the nulls and from their location and count
|
|
# determine the encoding. Also detect a BOM, if present.
|
|
sample = data[:4]
|
|
if sample in (codecs.BOM_UTF32_LE, codecs.BOM_UTF32_BE):
|
|
return 'utf-32' # BOM included
|
|
if sample[:3] == codecs.BOM_UTF8:
|
|
return 'utf-8-sig' # BOM included, MS style (discouraged)
|
|
if sample[:2] in (codecs.BOM_UTF16_LE, codecs.BOM_UTF16_BE):
|
|
return 'utf-16' # BOM included
|
|
nullcount = sample.count(_null)
|
|
if nullcount == 0:
|
|
return 'utf-8'
|
|
if nullcount == 2:
|
|
if sample[::2] == _null2: # 1st and 3rd are null
|
|
return 'utf-16-be'
|
|
if sample[1::2] == _null2: # 2nd and 4th are null
|
|
return 'utf-16-le'
|
|
# Did not detect 2 valid UTF-16 ascii-range characters
|
|
if nullcount == 3:
|
|
if sample[:3] == _null3:
|
|
return 'utf-32-be'
|
|
if sample[1:] == _null3:
|
|
return 'utf-32-le'
|
|
# Did not detect a valid UTF-32 ascii-range character
|
|
return None
|
|
|
|
|
|
def prepend_scheme_if_needed(url, new_scheme):
|
|
"""Given a URL that may or may not have a scheme, prepend the given scheme.
|
|
Does not replace a present scheme with the one provided as an argument.
|
|
|
|
:rtype: str
|
|
"""
|
|
scheme, netloc, path, params, query, fragment = urlparse(url, new_scheme)
|
|
|
|
# urlparse is a finicky beast, and sometimes decides that there isn't a
|
|
# netloc present. Assume that it's being over-cautious, and switch netloc
|
|
# and path if urlparse decided there was no netloc.
|
|
if not netloc:
|
|
netloc, path = path, netloc
|
|
|
|
return urlunparse((scheme, netloc, path, params, query, fragment))
|
|
|
|
|
|
def get_auth_from_url(url):
|
|
"""Given a url with authentication components, extract them into a tuple of
|
|
username,password.
|
|
|
|
:rtype: (str,str)
|
|
"""
|
|
parsed = urlparse(url)
|
|
|
|
try:
|
|
auth = (unquote(parsed.username), unquote(parsed.password))
|
|
except (AttributeError, TypeError):
|
|
auth = ('', '')
|
|
|
|
return auth
|
|
|
|
|
|
# Moved outside of function to avoid recompile every call
|
|
_CLEAN_HEADER_REGEX_BYTE = re.compile(b'^\\S[^\\r\\n]*$|^$')
|
|
_CLEAN_HEADER_REGEX_STR = re.compile(r'^\S[^\r\n]*$|^$')
|
|
|
|
def check_header_validity(header):
|
|
"""Verifies that header value is a string which doesn't contain
|
|
leading whitespace or return characters. This prevents unintended
|
|
header injection.
|
|
|
|
:param header: tuple, in the format (name, value).
|
|
"""
|
|
name, value = header
|
|
|
|
if isinstance(value, bytes):
|
|
pat = _CLEAN_HEADER_REGEX_BYTE
|
|
else:
|
|
pat = _CLEAN_HEADER_REGEX_STR
|
|
try:
|
|
if not pat.match(value):
|
|
raise InvalidHeader("Invalid return character or leading space in header: %s" % name)
|
|
except TypeError:
|
|
raise InvalidHeader("Header value %s must be of type str or bytes, "
|
|
"not %s" % (value, type(value)))
|
|
|
|
|
|
def urldefragauth(url):
|
|
"""
|
|
Given a url remove the fragment and the authentication part.
|
|
|
|
:rtype: str
|
|
"""
|
|
scheme, netloc, path, params, query, fragment = urlparse(url)
|
|
|
|
# see func:`prepend_scheme_if_needed`
|
|
if not netloc:
|
|
netloc, path = path, netloc
|
|
|
|
netloc = netloc.rsplit('@', 1)[-1]
|
|
|
|
return urlunparse((scheme, netloc, path, params, query, ''))
|
|
|
|
def rewind_body(prepared_request):
|
|
"""Move file pointer back to its recorded starting position
|
|
so it can be read again on redirect.
|
|
"""
|
|
body_seek = getattr(prepared_request.body, 'seek', None)
|
|
if body_seek is not None and isinstance(prepared_request._body_position, integer_types):
|
|
try:
|
|
body_seek(prepared_request._body_position)
|
|
except (IOError, OSError):
|
|
raise UnrewindableBodyError("An error occured when rewinding request "
|
|
"body for redirect.")
|
|
else:
|
|
raise UnrewindableBodyError("Unable to rewind request body for redirect.")
|