Edit File: url.py
from __future__ import absolute_import from collections import namedtuple import re from ..exceptions import LocationParseError from ..packages.six.moves.urllib.parse import quote url_attrs = ['scheme', 'auth', 'host', 'port', 'path', 'query', 'fragment'] # We only want to normalize urls with an HTTP(S) scheme. # urllib3 infers URLs without a scheme (None) to be http. NORMALIZABLE_SCHEMES = ('http', 'https', None) _contains_disallowed_url_pchar_re = re.compile('[\x00-\x20\x7f]') class Url(namedtuple('Url', url_attrs)): """ Datastructure for representing an HTTP URL. Used as a return value for :func:`parse_url`. Both the scheme and host are normalized as they are both case-insensitive according to RFC 3986. """ __slots__ = () def __new__(cls, scheme=None, auth=None, host=None, port=None, path=None, query=None, fragment=None): if path and not path.startswith('/'): path = '/' + path if scheme: scheme = scheme.lower() if host and scheme in NORMALIZABLE_SCHEMES: host = host.lower() return super(Url, cls).__new__(cls, scheme, auth, host, port, path, query, fragment) @property def hostname(self): """For backwards-compatibility with urlparse. We're nice like that.""" return self.host @property def request_uri(self): """Absolute path including the query string.""" uri = self.path or '/' if self.query is not None: uri += '?' + self.query return uri @property def netloc(self): """Network location including host and port""" if self.port: return '%s:%d' % (self.host, self.port) return self.host @property def url(self): """ Convert self into a url This function should more or less round-trip with :func:`.parse_url`. The returned url may not be exactly the same as the url inputted to :func:`.parse_url`, but it should be equivalent by the RFC (e.g., urls with a blank port will have : removed). Example: :: >>> U = parse_url('http://google.com/mail/') >>> U.url 'http://google.com/mail/' >>> Url('http', 'username:password', 'host.com', 80, ... '/path', 'query', 'fragment').url 'http://username:password@host.com:80/path?query#fragment' """ scheme, auth, host, port, path, query, fragment = self url = '' # We use "is not None" we want things to happen with empty strings (or 0 port) if scheme is not None: url += scheme + '://' if auth is not None: url += auth + '@' if host is not None: url += host if port is not None: url += ':' + str(port) if path is not None: url += path if query is not None: url += '?' + query if fragment is not None: url += '#' + fragment return url def __str__(self): return self.url def split_first(s, delims): """ Given a string and an iterable of delimiters, split on the first found delimiter. Return two split parts and the matched delimiter. If not found, then the first part is the full input string. Example:: >>> split_first('foo/bar?baz', '?/=') ('foo', 'bar?baz', '/') >>> split_first('foo/bar?baz', '123') ('foo/bar?baz', '', None) Scales linearly with number of delims. Not ideal for large number of delims. """ min_idx = None min_delim = None for d in delims: idx = s.find(d) if idx < 0: continue if min_idx is None or idx < min_idx: min_idx = idx min_delim = d if min_idx is None or min_idx < 0: return s, '', None return s[:min_idx], s[min_idx + 1:], min_delim def parse_url(url): """ Given a url, return a parsed :class:`.Url` namedtuple. Best-effort is performed to parse incomplete urls. Fields not provided will be None. Partly backwards-compatible with :mod:`urlparse`. Example:: >>> parse_url('http://google.com/mail/') Url(scheme='http', host='google.com', port=None, path='/mail/', ...) >>> parse_url('google.com:80') Url(scheme=None, host='google.com', port=80, path=None, ...) >>> parse_url('/foo?bar') Url(scheme=None, host=None, port=None, path='/foo', query='bar', ...) """ # While this code has overlap with stdlib's urlparse, it is much # simplified for our needs and less annoying. # Additionally, this implementations does silly things to be optimal # on CPython. if not url: # Empty return Url() # Prevent CVE-2019-9740. # adapted from https://github.com/python/cpython/pull/12755 url = _contains_disallowed_url_pchar_re.sub(lambda match: quote(match.group()), url) scheme = None auth = None host = None port = None path = None fragment = None query = None # Scheme if '://' in url: scheme, url = url.split('://', 1) # Find the earliest Authority Terminator # (http://tools.ietf.org/html/rfc3986#section-3.2) url, path_, delim = split_first(url, ['/', '?', '#']) if delim: # Reassemble the path path = delim + path_ # Auth if '@' in url: # Last '@' denotes end of auth part auth, url = url.rsplit('@', 1) # IPv6 if url and url[0] == '[': host, url = url.split(']', 1) host += ']' # Port if ':' in url: _host, port = url.split(':', 1) if not host: host = _host if port: # If given, ports must be integers. No whitespace, no plus or # minus prefixes, no non-integer digits such as ^2 (superscript). if not port.isdigit(): raise LocationParseError(url) try: port = int(port) except ValueError: raise LocationParseError(url) else: # Blank ports are cool, too. (rfc3986#section-3.2.3) port = None elif not host and url: host = url if not path: return Url(scheme, auth, host, port, path, query, fragment) # Fragment if '#' in path: path, fragment = path.split('#', 1) # Query if '?' in path: path, query = path.split('?', 1) return Url(scheme, auth, host, port, path, query, fragment) def get_host(url): """ Deprecated. Use :func:`parse_url` instead. """ p = parse_url(url) return p.scheme or 'http', p.hostname, p.port
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