Source code for pook.headers
try:
from collections.abc import Mapping, MutableMapping
except ImportError:
from collections import Mapping, MutableMapping
[docs]
class HTTPHeaderDict(MutableMapping):
"""
:param headers:
An iterable of field-value pairs. Must not contain multiple field names
when compared case-insensitively.
:param kwargs:
Additional field-value pairs to pass in to ``dict.update``.
A ``dict`` like container for storing HTTP Headers.
Field names are stored and compared case-insensitively in compliance with
RFC 7230. Iteration provides the first case-sensitive key seen for each
case-insensitive pair.
Using ``__setitem__`` syntax overwrites fields that compare equal
case-insensitively in order to maintain ``dict``'s api. For fields that
compare equal, instead create a new ``HTTPHeaderDict`` and use ``.add``
in a loop.
If multiple fields that are equal case-insensitively are passed to the
constructor or ``.update``, the behavior is undefined and some will be
lost.
Usage::
headers = HTTPHeaderDict()
headers.add('Set-Cookie', 'foo=bar')
headers.add('set-cookie', 'baz=quxx')
headers['content-length'] = '7'
headers['SET-cookie']
> 'foo=bar, baz=quxx'
headers['Content-Length']
> '7'
"""
def __init__(self, headers=None, **kwargs):
super(HTTPHeaderDict, self).__init__()
self._container = {}
if headers is not None:
if isinstance(headers, HTTPHeaderDict):
self._copy_from(headers)
else:
self.extend(headers)
if kwargs:
self.extend(kwargs)
def __setitem__(self, key, val):
self._container[key.lower()] = (key, val)
return self._container[key.lower()]
def __getitem__(self, key):
val = self._container[key.lower()]
return ", ".join([to_string_value(v) for v in val[1:]])
def __delitem__(self, key):
del self._container[key.lower()]
def __contains__(self, key):
return key.lower() in self._container
def __eq__(self, other):
if not isinstance(other, Mapping) and not hasattr(other, "keys"):
return False
if not isinstance(other, type(self)):
other = type(self)(other)
return dict((k.lower(), v) for k, v in self.itermerged()) == dict(
(k.lower(), v) for k, v in other.itermerged()
)
def __ne__(self, other):
return not self.__eq__(other)
__marker = object()
def __len__(self):
return len(self._container)
def __iter__(self):
# Only provide the originally cased names
for vals in self._container.values():
yield vals[0]
[docs]
def pop(self, key, default=__marker):
"""
D.pop(k[,d]) -> v, remove specified key and return the
corresponding value.
If key is not found, d is returned if given, otherwise KeyError
is raised.
"""
# Using the MutableMapping function directly fails due to the
# private marker. Using ordinary dict.pop would expose the
# internal structures. So let's reinvent the wheel.
try:
value = self[key]
except KeyError:
if default is self.__marker:
raise
return default
else:
del self[key]
return value
[docs]
def add(self, key, val):
"""
Adds a (name, value) pair, doesn't overwrite the value if it already
exists.
Usage::
headers = HTTPHeaderDict(foo='bar')
headers.add('Foo', 'baz')
headers['foo']
> 'bar, baz'
"""
key_lower = key.lower()
new_vals = key, val
# Keep the common case aka no item present as fast as possible
vals = self._container.setdefault(key_lower, new_vals)
if new_vals is not vals:
# new_vals was not inserted, as there was a previous one
if isinstance(vals, list):
# If already several items got inserted, we have a list
vals.append(val)
else:
# vals should be a tuple then, i.e. only one item so far
# Need to convert the tuple to list for further extension
self._container[key_lower] = [vals[0], vals[1], val]
[docs]
def set(self, key, val):
"""
Sets a header field with the given value, removing
previous values.
Usage::
headers = HTTPHeaderDict(foo='bar')
headers.set('Foo', 'baz')
headers['foo']
> 'baz'
"""
key_lower = key.lower()
new_vals = key, val
# Keep the common case aka no item present as fast as possible
vals = self._container.setdefault(key_lower, new_vals)
if new_vals is not vals:
self._container[key_lower] = [vals[0], vals[1], val]
[docs]
def extend(self, mapping, **kwargs):
"""
Generic import function for any type of header-like object.
Adapted version of MutableMapping.update in order to insert items
with self.add instead of self.__setitem__
"""
if isinstance(mapping, HTTPHeaderDict):
for key, val in mapping.iteritems():
self.add(key, val)
elif isinstance(mapping, Mapping):
for key in mapping:
self.add(key, mapping[key])
elif hasattr(mapping, "keys"):
for key in mapping.keys():
self.add(key, mapping[key])
else:
for key, value in mapping:
self.add(key, value)
for key, value in kwargs.items():
self.add(key, value)
[docs]
def getlist(self, key):
"""
Returns a list of all the values for the named field.
Returns an empty list if the key doesn't exist.
"""
try:
vals = self._container[key.lower()]
except KeyError:
return []
else:
if isinstance(vals, tuple):
return [vals[1]]
else:
return vals[1:]
# Backwards compatibility for httplib
getheaders = getlist
getallmatchingheaders = getlist
iget = getlist
def __repr__(self):
return "%s(%s)" % (type(self).__name__, dict(self.itermerged()))
def _copy_from(self, other):
for key in other:
val = other.getlist(key)
if isinstance(val, list):
# Don't need to convert tuples
val = list(val)
self._container[key.lower()] = [key] + val
[docs]
def iteritems(self):
"""
Iterate over all header lines, including duplicate ones.
"""
for key in self:
vals = self._container[key.lower()]
for val in vals[1:]:
yield vals[0], val
[docs]
def itermerged(self):
"""
Iterate over all headers, merging duplicate ones together.
"""
for key in self:
val = self._container[key.lower()]
yield val[0], ", ".join([to_string_value(v) for v in val[1:]])
[docs]
def to_string_value(value):
"""
Retrieve a string value for an arbitrary value.
HTTP header values are specified as ASCII strings. However,
the specificiation also states that non-ASCII bytes should be
treated as arbitrary data. In that case, we just rely on unicode
escaping to return a value that at least somewhat resembles the
inputs (at least moreso than other encodings that would significantly
obscure the input, like base 64).
Arguments::
value (mixed):
The value to cast to ``str``.
Returns::
str:
Unicode escaped ``value`` if it was ``bytes``; otherwise,
``value`` is returned, cast through ``str``.
"""
if hasattr(value, "decode"):
return value.decode("unicode_escape")
return str(value)