# -*- coding: utf-8 -*-
"""
requests.utils
~~~~~~~~~~~~~~
This module provides utility functions that are used within Requests
that are also useful for external consumption.
"""
import cgi
import codecs
import collections
import io
import os
import platform
import re
import sys
import socket
import struct
from . import __version__
from . import certs
from .compat import parse_http_list as _parse_list_header
from .compat import (quote, urlparse, bytes, str, OrderedDict, unquote, is_py2,
builtin_str, getproxies, proxy_bypass)
from .cookies import RequestsCookieJar, cookiejar_from_dict
from .structures import CaseInsensitiveDict
from .exceptions import MissingSchema, InvalidURL
_hush_pyflakes = (RequestsCookieJar,)
NETRC_FILES = ('.netrc', '_netrc')
DEFAULT_CA_BUNDLE_PATH = certs.where()
def dict_to_sequence(d):
"""Returns an internal sequence dictionary update."""
if hasattr(d, 'items'):
d = d.items()
return d
def super_len(o):
if hasattr(o, '__len__'):
return len(o)
if hasattr(o, 'len'):
return o.len
if hasattr(o, 'fileno'):
try:
fileno = o.fileno()
except io.UnsupportedOperation:
pass
else:
return os.fstat(fileno).st_size
if hasattr(o, 'getvalue'):
# e.g. BytesIO, cStringIO.StringIO
return len(o.getvalue())
def get_netrc_auth(url):
"""Returns the Requests tuple auth for a given url from netrc."""
try:
from netrc import netrc, NetrcParseError
netrc_path = None
for f in NETRC_FILES:
try:
loc = os.path.expanduser('~/{0}'.format(f))
except KeyError:
# os.path.expanduser can fail when $HOME is undefined and
# getpwuid fails. See http://bugs.python.org/issue20164 &
# https://github.com/kennethreitz/requests/issues/1846
return
if os.path.exists(loc):
netrc_path = loc
break
# Abort early if there isn't one.
if netrc_path is None:
return
ri = urlparse(url)
# Strip port numbers from netloc
host = ri.netloc.split(':')[0]
try:
_netrc = netrc(netrc_path).authenticators(host)
if _netrc:
# Return with login / password
login_i = (0 if _netrc[0] else 1)
return (_netrc[login_i], _netrc[2])
except (NetrcParseError, IOError):
# If there was a parsing error or a permissions issue reading the file,
# we'll just skip netrc auth
pass
# AppEngine hackiness.
except (ImportError, AttributeError):
pass
def guess_filename(obj):
"""Tries to guess the filename of the given object."""
name = getattr(obj, 'name', None)
if name and name[0] != '<' and name[-1] != '>':
return os.path.basename(name)
def from_key_val_list(value):
"""Take an object and test to see if it can be represented as a
dictionary. Unless it can not be represented as such, return an
OrderedDict, e.g.,
::
>>> from_key_val_list([('key', 'val')])
OrderedDict([('key', 'val')])
>>> from_key_val_list('string')
ValueError: need more than 1 value to unpack
>>> from_key_val_list({'key': 'val'})
OrderedDict([('key', 'val')])
"""
if value is None:
return None
if isinstance(value, (str, bytes, bool, int)):
raise ValueError('cannot encode objects that are not 2-tuples')
return OrderedDict(value)
def to_key_val_list(value):
"""Take an object and test to see if it can be represented as a
dictionary. If it can be, return a list of tuples, e.g.,
::
>>> to_key_val_list([('key', 'val')])
[('key', 'val')]
>>> to_key_val_list({'key': 'val'})
[('key', 'val')]
>>> to_key_val_list('string')
ValueError: cannot encode objects that are not 2-tuples.
"""
if value is None:
return None
if isinstance(value, (str, bytes, bool, int)):
raise ValueError('cannot encode objects that are not 2-tuples')
if isinstance(value, collections.Mapping):
value = value.items()
return list(value)
# From mitsuhiko/werkzeug (used with permission).
def parse_list_header(value):
"""Parse lists as described by RFC 2068 Section 2.
In particular, parse comma-separated lists where the elements of
the list may include quoted-strings. A quoted-string could
contain a comma. A non-quoted string could have quotes in the
middle. Quotes are removed automatically after parsing.
It basically works like :func:`parse_set_header` just that items
may appear multiple times and case sensitivity is preserved.
The return value is a standard :class:`list`:
>>> parse_list_header('token, "quoted value"')
['token', 'quoted value']
To create a header from the :class:`list` again, use the
:func:`dump_header` function.
:param value: a string with a list header.
:return: :class:`list`
"""
result = []
for item in _parse_list_header(value):
if item[:1] == item[-1:] == '"':
item = unquote_header_value(item[1:-1])
result.append(item)
return result
# From mitsuhiko/werkzeug (used with permission).
def parse_dict_header(value):
"""Parse lists of key, value pairs as described by RFC 2068 Section 2 and
convert them into a python dict:
>>> d = parse_dict_header('foo="is a fish", bar="as well"')
>>> type(d) is dict
True
>>> sorted(d.items())
[('bar', 'as well'), ('foo', 'is a fish')]
If there is no value for a key it will be `None`:
>>> parse_dict_header('key_without_value')
{'key_without_value': None}
To create a header from the :class:`dict` again, use the
:func:`dump_header` function.
:param value: a string with a dict header.
:return: :class:`dict`
"""
result = {}
for item in _parse_list_header(value):
if '=' not in item:
result[item] = None
continue
name, value = item.split('=', 1)
if value[:1] == value[-1:] == '"':
value = unquote_header_value(value[1:-1])
result[name] = value
return result
# From mitsuhiko/werkzeug (used with permission).
def unquote_header_value(value, is_filename=False):
r"""Unquotes a header value. (Reversal of :func:`quote_header_value`).
This does not use the real unquoting but what browsers are actually
using for quoting.
:param value: the header value to unquote.
"""
if value and value[0] == value[-1] == '"':
# this is not the real unquoting, but fixing this so that the
# RFC is met will result in bugs with internet explorer and
# probably some other browsers as well. IE for example is
# uploading files with "C:\foo\bar.txt" as filename
value = value[1:-1]
# if this is a filename and the starting characters look like
# a UNC path, then just return the value without quotes. Using the
# replace sequence below on a UNC path has the effect of turning
# the leading double slash into a single slash and then
# _fix_ie_filename() doesn't work correctly. See #458.
if not is_filename or value[:2] != '\\\\':
return value.replace('\\\\', '\\').replace('\\"', '"')
return value
def dict_from_cookiejar(cj):
"""Returns a key/value dictionary from a CookieJar.
:param cj: CookieJar object to extract cookies from.
"""
cookie_dict = {}
for cookie in cj:
cookie_dict[cookie.name] = cookie.value
return cookie_dict
def add_dict_to_cookiejar(cj, cookie_dict):
"""Returns a CookieJar from a key/value dictionary.
:param cj: CookieJar to insert cookies into.
:param cookie_dict: Dict of key/values to insert into CookieJar.
"""
cj2 = cookiejar_from_dict(cookie_dict)
cj.update(cj2)
return cj
def get_encodings_from_content(content):
"""Returns encodings from given content string.
:param content: bytestring to extract encodings from.
"""
charset_re = re.compile(r'<meta.*?charset=["\']*(.+?)["\'>]', flags=re.I)
pragma_re = re.compile(r'<meta.*?content=["\']*;?charset=(.+?)["\'>]', flags=re.I)
xml_re = re.compile(r'^<\?xml.*?encoding=["\']*(.+?)["\'>]')
return (charset_re.findall(content) +
pragma_re.findall(content) +
xml_re.findall(content))
def get_encoding_from_headers(headers):
"""Returns encodings from given HTTP Header Dict.
:param headers: dictionary to extract encoding from.
"""
content_type = headers.get('content-type')
if not content_type:
return None
content_type, params = cgi.parse_header(content_type)
if 'charset' in params:
return params['charset'].strip("'\"")
if 'text' in content_type:
return 'ISO-8859-1'
def stream_decode_response_unicode(iterator, r):
"""Stream decodes a iterator."""
if r.encoding is None:
for item in iterator:
yield item
return
decoder = codecs.getincrementaldecoder(r.encoding)(errors='replace')
for chunk in iterator:
rv = decoder.decode(chunk)
if rv:
yield rv
rv = decoder.decode(b'', final=True)
if rv:
yield rv
def iter_slices(string, slice_length):
"""Iterate over slices of a string."""
pos = 0
while pos < len(string):
yield string[pos:pos + slice_length]
pos += slice_length
def get_unicode_from_response(r):
"""Returns the requested content back in unicode.
:param r: Response object to get unicode content from.
Tried:
1. charset from content-type
2. every encodings from ``<meta ... charset=XXX>``
3. fall back and replace all unicode characters
"""
tried_encodings = []
# Try charset from content-type
encoding = get_encoding_from_headers(r.headers)
if encoding:
try:
return str(r.content, encoding)
except UnicodeError:
tried_encodings.append(encoding)
# Fall back:
try:
return str(r.content, encoding, errors='replace')
except TypeError:
return r.content
# The unreserved URI characters (RFC 3986)
UNRESERVED_SET = frozenset(
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+ "0123456789-._~")
def unquote_unreserved(uri):
"""Un-escape any percent-escape sequences in a URI that are unreserved
characters. This leaves all reserved, illegal and non-ASCII bytes encoded.
"""
parts = uri.split('%')
for i in range(1, len(parts)):
h = parts[i][0:2]
if len(h) == 2 and h.isalnum():
try:
c = chr(int(h, 16))
except ValueError:
raise InvalidURL("Invalid percent-escape sequence: '%s'" % h)
if c in UNRESERVED_SET:
parts[i] = c + parts[i][2:]
else:
parts[i] = '%' + parts[i]
else:
parts[i] = '%' + parts[i]
return ''.join(parts)
def requote_uri(uri):
"""Re-quote the given URI.
This function passes the given URI through an unquote/quote cycle to
ensure that it is fully and consistently quoted.
"""
# Unquote only the unreserved characters
# Then quote only illegal characters (do not quote reserved, unreserved,
# or '%')
return quote(unquote_unreserved(uri), safe="!#$%&'()*+,/:;=?@[]~")
def address_in_network(ip, net):
"""
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
returns False if ip = 192.168.1.1 and net = 192.168.100.0/24
"""
ipaddr = struct.unpack('=L', socket.inet_aton(ip))[0]
netaddr, bits = net.split('/')
netmask = struct.unpack('=L', socket.inet_aton(dotted_netmask(int(bits))))[0]
network = struct.unpack('=L', socket.inet_aton(netaddr))[0] & netmask
return (ipaddr & netmask) == (network & netmask)
def dotted_netmask(mask):
"""
Converts mask from /xx format to xxx.xxx.xxx.xxx
Example: if mask is 24 function returns 255.255.255.0
"""
bits = 0xffffffff ^ (1 << 32 - mask) - 1
return socket.inet_ntoa(struct.pack('>I', bits))
def is_ipv4_address(string_ip):
try:
socket.inet_aton(string_ip)
except socket.error:
return False
return True
def is_valid_cidr(string_network):
"""Very simple check of the cidr format in no_proxy variable"""
if string_network.count('/') == 1:
try:
mask = int(string_network.split('/')[1])
except ValueError:
return False
if mask < 1 or mask > 32:
return False
try:
socket.inet_aton(string_network.split('/')[0])
except socket.error:
return False
else:
return False
return True
def should_bypass_proxies(url):
"""
Returns whether we should bypass proxies or not.
"""
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 = no_proxy.replace(' ', '').split(',')
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
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."""
if should_bypass_proxies(url):
return {}
else:
return getproxies()
def default_user_agent(name="python-requests"):
"""Return a string representing the default user agent."""
_implementation = platform.python_implementation()
if _implementation == 'CPython':
_implementation_version = platform.python_version()
elif _implementation == 'PyPy':
_implementation_version = '%s.%s.%s' % (sys.pypy_version_info.major,
sys.pypy_version_info.minor,
sys.pypy_version_info.micro)
if sys.pypy_version_info.releaselevel != 'final':
_implementation_version = ''.join([_implementation_version, sys.pypy_version_info.releaselevel])
elif _implementation == 'Jython':
_implementation_version = platform.python_version() # Complete Guess
elif _implementation == 'IronPython':
_implementation_version = platform.python_version() # Complete Guess
else:
_implementation_version = 'Unknown'
try:
p_system = platform.system()
p_release = platform.release()
except IOError:
p_system = 'Unknown'
p_release = 'Unknown'
return " ".join(['%s/%s' % (name, __version__),
'%s/%s' % (_implementation, _implementation_version),
'%s/%s' % (p_system, p_release)])
def default_headers():
return CaseInsensitiveDict({
'User-Agent': default_user_agent(),
'Accept-Encoding': ', '.join(('gzip', 'deflate')),
'Accept': '*/*'
})
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"
"""
links = []
replace_chars = " '\""
for val in value.split(","):
try:
url, params = val.split(";", 1)
except ValueError:
url, params = val, ''
link = {}
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):
# 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.BOM32_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 except_on_missing_scheme(url):
"""Given a URL, raise a MissingSchema exception if the scheme is missing.
"""
scheme, netloc, path, params, query, fragment = urlparse(url)
if not scheme:
raise MissingSchema('Proxy URLs must have explicit schemes.')
def get_auth_from_url(url):
"""Given a url with authentication components, extract them into a tuple of
username,password."""
parsed = urlparse(url)
try:
auth = (unquote(parsed.username), unquote(parsed.password))
except (AttributeError, TypeError):
auth = ('', '')
return auth
def to_native_string(string, encoding='ascii'):
"""
Given a string object, regardless of type, returns a representation of that
string in the native string type, encoding and decoding where necessary.
This assumes ASCII unless told otherwise.
"""
out = None
if isinstance(string, builtin_str):
out = string
else:
if is_py2:
out = string.encode(encoding)
else:
out = string.decode(encoding)
return out