From 19346fa9068878af516cdb670bea4f791337507b Mon Sep 17 00:00:00 2001 From: Thibaut Horel Date: Sun, 29 Sep 2013 05:12:56 -0400 Subject: Initial commit --- requests/utils.py | 401 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 401 insertions(+) create mode 100644 requests/utils.py (limited to 'requests/utils.py') diff --git a/requests/utils.py b/requests/utils.py new file mode 100644 index 0000000..95dea4b --- /dev/null +++ b/requests/utils.py @@ -0,0 +1,401 @@ +# -*- 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 cookielib +import os +import random +import re +import zlib +import urllib + +from urllib2 import parse_http_list as _parse_list_header + + +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 name + +# 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 header_expand(headers): + """Returns an HTTP Header value string from a dictionary. + + Example expansion:: + + {'text/x-dvi': {'q': '.8', 'mxb': '100000', 'mxt': '5.0'}, 'text/x-c': {}} + # Accept: text/x-dvi; q=.8; mxb=100000; mxt=5.0, text/x-c + + (('text/x-dvi', {'q': '.8', 'mxb': '100000', 'mxt': '5.0'}), ('text/x-c', {})) + # Accept: text/x-dvi; q=.8; mxb=100000; mxt=5.0, text/x-c + """ + + collector = [] + + if isinstance(headers, dict): + headers = headers.items() + + elif isinstance(headers, basestring): + return headers + + for i, (value, params) in enumerate(headers): + + _params = [] + + for (p_k, p_v) in params.items(): + + _params.append('%s=%s' % (p_k, p_v)) + + collector.append(value) + collector.append('; ') + + if len(params): + + collector.append('; '.join(_params)) + + if not len(headers) == i+1: + collector.append(', ') + + + # Remove trailing separators. + if collector[-1] in (', ', '; '): + del collector[-1] + + return ''.join(collector) + + + +def randombytes(n): + """Return n random bytes.""" + # Use /dev/urandom if it is available. Fall back to random module + # if not. It might be worthwhile to extend this function to use + # other platform-specific mechanisms for getting random bytes. + if os.path.exists("/dev/urandom"): + f = open("/dev/urandom") + s = f.read(n) + f.close() + return s + else: + L = [chr(random.randrange(0, 256)) for i in range(n)] + return "".join(L) + + +def dict_from_cookiejar(cj): + """Returns a key/value dictionary from a CookieJar. + + :param cj: CookieJar object to extract cookies from. + """ + + cookie_dict = {} + + for _, cookies in cj._cookies.items(): + for _, cookies in cookies.items(): + for cookie in cookies.values(): + # print cookie + cookie_dict[cookie.name] = cookie.value + + return cookie_dict + + +def cookiejar_from_dict(cookie_dict): + """Returns a CookieJar from a key/value dictionary. + + :param cookie_dict: Dict of key/values to insert into CookieJar. + """ + + # return cookiejar if one was passed in + if isinstance(cookie_dict, cookielib.CookieJar): + return cookie_dict + + # create cookiejar + cj = cookielib.CookieJar() + + cj = add_dict_to_cookiejar(cj, cookie_dict) + + return cj + + +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. + """ + + for k, v in cookie_dict.items(): + + cookie = cookielib.Cookie( + version=0, + name=k, + value=v, + port=None, + port_specified=False, + domain='', + domain_specified=False, + domain_initial_dot=False, + path='/', + path_specified=True, + secure=False, + expires=None, + discard=True, + comment=None, + comment_url=None, + rest={'HttpOnly': None}, + rfc2109=False + ) + + # add cookie to cookiejar + cj.set_cookie(cookie) + + 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']', flags=re.I) + + return charset_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 unicode_from_html(content): + """Attempts to decode an HTML string into unicode. + If unsuccessful, the original content is returned. + """ + + encodings = get_encodings_from_content(content) + + for encoding in encodings: + + try: + return unicode(content, encoding) + except (UnicodeError, TypeError): + pass + + return content + + +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('', final=True) + if rv: + yield rv + + +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 ```` + + 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 unicode(r.content, encoding) + except UnicodeError: + tried_encodings.append(encoding) + + # Fall back: + try: + return unicode(r.content, encoding, errors='replace') + except TypeError: + return r.content + + +def decode_gzip(content): + """Return gzip-decoded string. + + :param content: bytestring to gzip-decode. + """ + + return zlib.decompress(content, 16 + zlib.MAX_WBITS) + + +def stream_decompress(iterator, mode='gzip'): + """ + Stream decodes an iterator over compressed data + + :param iterator: An iterator over compressed data + :param mode: 'gzip' or 'deflate' + :return: An iterator over decompressed data + """ + + if mode not in ['gzip', 'deflate']: + raise ValueError('stream_decompress mode must be gzip or deflate') + + zlib_mode = 16 + zlib.MAX_WBITS if mode == 'gzip' else -zlib.MAX_WBITS + dec = zlib.decompressobj(zlib_mode) + try: + for chunk in iterator: + rv = dec.decompress(chunk) + if rv: + yield rv + except zlib.error: + # If there was an error decompressing, just return the raw chunk + yield chunk + # Continue to return the rest of the raw data + for chunk in iterator: + yield chunk + else: + # Make sure everything has been returned from the decompression object + buf = dec.decompress('') + rv = buf + dec.flush() + if rv: + yield rv + + +def requote_path(path): + """Re-quote the given URL path component. + + This function passes the given path through an unquote/quote cycle to + ensure that it is fully and consistently quoted. + """ + parts = path.split("/") + parts = (urllib.quote(urllib.unquote(part), safe="") for part in parts) + return "/".join(parts) -- cgit v1.2.3-70-g09d2