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# -*- coding: utf-8 -*-


Data structures that power Requests.

import collections

from .compat import OrderedDict

class CaseInsensitiveDict(collections.MutableMapping):
"""A case-insensitive ``dict``-like object.

Implements all methods and operations of
``collections.MutableMapping`` as well as dict's ``copy``. Also
provides ``lower_items``.

All keys are expected to be strings. The structure remembers the
case of the last key to be set, and ``iter(instance)``,
``keys()``, ``items()``, ``iterkeys()``, and ``iteritems()``
will contain case-sensitive keys. However, querying and contains
testing is case insensitive::

cid = CaseInsensitiveDict()
cid['Accept'] = 'application/json'
cid['aCCEPT'] == 'application/json' # True
list(cid) == ['Accept'] # True

For example, ``headers['content-encoding']`` will return the
value of a ``'Content-Encoding'`` response header, regardless
of how the header name was originally stored.

If the constructor, ``.update``, or equality comparison
operations are given keys that have equal ``.lower()``s, the
behavior is undefined.

def __init__(self, data=None, **kwargs):
self._store = OrderedDict()
if data is None:
data = {}
self.update(data, **kwargs)

def __setitem__(self, key, value):
# Use the lowercased key for lookups, but store the actual
# key alongside the value.
self._store[key.lower()] = (key, value)

def __getitem__(self, key):
return self._store[key.lower()][1]

def __delitem__(self, key):
del self._store[key.lower()]

def __iter__(self):
return (casedkey for casedkey, mappedvalue in self._store.values())

def __len__(self):
return len(self._store)

def lower_items(self):
"""Like iteritems(), but with all lowercase keys."""
return (
(lowerkey, keyval[1])
for (lowerkey, keyval)
in self._store.items()

def __eq__(self, other):
if isinstance(other, collections.Mapping):
other = CaseInsensitiveDict(other)
return NotImplemented
# Compare insensitively
return dict(self.lower_items()) == dict(other.lower_items())

# Copy is required
def copy(self):
return CaseInsensitiveDict(self._store.values())

def __repr__(self):
return str(dict(self.items()))

class LookupDict(dict):
"""Dictionary lookup object."""

def __init__(self, name=None): = name
super(LookupDict, self).__init__()

def __repr__(self):
return '' % (

def __getitem__(self, key):
# We allow fall-through here, so values default to None

return self.__dict__.get(key, None)

def get(self, key, default=None):
return self.__dict__.get(key, default)

This post first appeared on Ricky's Python Notes, please read the originial post: here

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