Source code for w3lib.http
from base64 import b64encode
from typing import Any, AnyStr, List, Mapping, MutableMapping, Optional, Sequence, Union
from w3lib.util import to_bytes, to_unicode
HeadersDictInput = Mapping[bytes, Union[Any, Sequence[bytes]]]
HeadersDictOutput = MutableMapping[bytes, List[bytes]]
[docs]def headers_raw_to_dict(headers_raw: Optional[bytes]) -> Optional[HeadersDictOutput]:
r"""
Convert raw headers (single multi-line bytestring)
to a dictionary.
For example:
>>> import w3lib.http
>>> w3lib.http.headers_raw_to_dict(b"Content-type: text/html\n\rAccept: gzip\n\n") # doctest: +SKIP
{'Content-type': ['text/html'], 'Accept': ['gzip']}
Incorrect input:
>>> w3lib.http.headers_raw_to_dict(b"Content-typt gzip\n\n")
{}
>>>
Argument is ``None`` (return ``None``):
>>> w3lib.http.headers_raw_to_dict(None)
>>>
"""
if headers_raw is None:
return None
headers = headers_raw.splitlines()
headers_tuples = [header.split(b":", 1) for header in headers]
result_dict: HeadersDictOutput = {}
for header_item in headers_tuples:
if not len(header_item) == 2:
continue
item_key = header_item[0].strip()
item_value = header_item[1].strip()
if item_key in result_dict:
result_dict[item_key].append(item_value)
else:
result_dict[item_key] = [item_value]
return result_dict
[docs]def headers_dict_to_raw(headers_dict: Optional[HeadersDictInput]) -> Optional[bytes]:
r"""
Returns a raw HTTP headers representation of headers
For example:
>>> import w3lib.http
>>> w3lib.http.headers_dict_to_raw({b'Content-type': b'text/html', b'Accept': b'gzip'}) # doctest: +SKIP
'Content-type: text/html\\r\\nAccept: gzip'
>>>
Note that keys and values must be bytes.
Argument is ``None`` (returns ``None``):
>>> w3lib.http.headers_dict_to_raw(None)
>>>
"""
if headers_dict is None:
return None
raw_lines = []
for key, value in headers_dict.items():
if isinstance(value, bytes):
raw_lines.append(b": ".join([key, value]))
elif isinstance(value, (list, tuple)):
for v in value:
raw_lines.append(b": ".join([key, v]))
return b"\r\n".join(raw_lines)
[docs]def basic_auth_header(
username: AnyStr, password: AnyStr, encoding: str = "ISO-8859-1"
) -> bytes:
"""
Return an `Authorization` header field value for `HTTP Basic Access Authentication (RFC 2617)`_
>>> import w3lib.http
>>> w3lib.http.basic_auth_header('someuser', 'somepass')
'Basic c29tZXVzZXI6c29tZXBhc3M='
.. _HTTP Basic Access Authentication (RFC 2617): http://www.ietf.org/rfc/rfc2617.txt
"""
auth = f"{to_unicode(username)}:{to_unicode(password)}"
# XXX: RFC 2617 doesn't define encoding, but ISO-8859-1
# seems to be the most widely used encoding here. See also:
# http://greenbytes.de/tech/webdav/draft-ietf-httpauth-basicauth-enc-latest.html
return b"Basic " + b64encode(to_bytes(auth, encoding=encoding))