cpython/Lib/urlparse.py

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"""Parse (absolute and relative) URLs.
See RFC 1808: "Relative Uniform Resource Locators", by R. Fielding,
UC Irvine, June 1995.
"""
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__all__ = ["urlparse", "urlunparse", "urljoin", "urldefrag",
"urlsplit", "urlunsplit"]
# A classification of schemes ('' means apply by default)
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uses_relative = ['ftp', 'http', 'gopher', 'nntp', 'imap',
'wais', 'file', 'https', 'shttp', 'mms',
'prospero', 'rtsp', 'rtspu', '', 'sftp']
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uses_netloc = ['ftp', 'http', 'gopher', 'nntp', 'telnet',
'imap', 'wais', 'file', 'mms', 'https', 'shttp',
'snews', 'prospero', 'rtsp', 'rtspu', 'rsync', '',
'svn', 'svn+ssh', 'sftp']
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non_hierarchical = ['gopher', 'hdl', 'mailto', 'news',
'telnet', 'wais', 'imap', 'snews', 'sip', 'sips']
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uses_params = ['ftp', 'hdl', 'prospero', 'http', 'imap',
'https', 'shttp', 'rtsp', 'rtspu', 'sip', 'sips',
'mms', '', 'sftp']
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uses_query = ['http', 'wais', 'imap', 'https', 'shttp', 'mms',
'gopher', 'rtsp', 'rtspu', 'sip', 'sips', '']
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uses_fragment = ['ftp', 'hdl', 'http', 'gopher', 'news',
'nntp', 'wais', 'https', 'shttp', 'snews',
'file', 'prospero', '']
# Characters valid in scheme names
scheme_chars = ('abcdefghijklmnopqrstuvwxyz'
'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
'0123456789'
'+-.')
MAX_CACHE_SIZE = 20
_parse_cache = {}
def clear_cache():
"""Clear the parse cache."""
global _parse_cache
_parse_cache = {}
class BaseResult(tuple):
"""Base class for the parsed result objects.
This provides the attributes shared by the two derived result
objects as read-only properties. The derived classes are
responsible for checking the right number of arguments were
supplied to the constructor.
"""
__slots__ = ()
# Attributes that access the basic components of the URL:
@property
def scheme(self):
return self[0]
@property
def netloc(self):
return self[1]
@property
def path(self):
return self[2]
@property
def query(self):
return self[-2]
@property
def fragment(self):
return self[-1]
# Additional attributes that provide access to parsed-out portions
# of the netloc:
@property
def username(self):
netloc = self.netloc
if "@" in netloc:
userinfo = netloc.split("@", 1)[0]
if ":" in userinfo:
userinfo = userinfo.split(":", 1)[0]
return userinfo
return None
@property
def password(self):
netloc = self.netloc
if "@" in netloc:
userinfo = netloc.split("@", 1)[0]
if ":" in userinfo:
return userinfo.split(":", 1)[1]
return None
@property
def hostname(self):
netloc = self.netloc
if "@" in netloc:
netloc = netloc.split("@", 1)[1]
if ":" in netloc:
netloc = netloc.split(":", 1)[0]
return netloc.lower() or None
@property
def port(self):
netloc = self.netloc
if "@" in netloc:
netloc = netloc.split("@", 1)[1]
if ":" in netloc:
port = netloc.split(":", 1)[1]
return int(port, 10)
return None
class SplitResult(BaseResult):
__slots__ = ()
def __new__(cls, scheme, netloc, path, query, fragment):
return BaseResult.__new__(
cls, (scheme, netloc, path, query, fragment))
def geturl(self):
return urlunsplit(self)
class ParseResult(BaseResult):
__slots__ = ()
def __new__(cls, scheme, netloc, path, params, query, fragment):
return BaseResult.__new__(
cls, (scheme, netloc, path, params, query, fragment))
@property
def params(self):
return self[3]
def geturl(self):
return urlunparse(self)
def urlparse(url, scheme='', allow_fragments=True):
"""Parse a URL into 6 components:
<scheme>://<netloc>/<path>;<params>?<query>#<fragment>
Return a 6-tuple: (scheme, netloc, path, params, query, fragment).
Note that we don't break the components up in smaller bits
(e.g. netloc is a single string) and we don't expand % escapes."""
tuple = urlsplit(url, scheme, allow_fragments)
scheme, netloc, url, query, fragment = tuple
if scheme in uses_params and ';' in url:
url, params = _splitparams(url)
else:
params = ''
return ParseResult(scheme, netloc, url, params, query, fragment)
def _splitparams(url):
if '/' in url:
i = url.find(';', url.rfind('/'))
if i < 0:
return url, ''
else:
i = url.find(';')
return url[:i], url[i+1:]
def _splitnetloc(url, start=0):
for c in '/?#': # the order is important!
delim = url.find(c, start)
if delim >= 0:
break
else:
delim = len(url)
return url[start:delim], url[delim:]
def urlsplit(url, scheme='', allow_fragments=True):
"""Parse a URL into 5 components:
<scheme>://<netloc>/<path>?<query>#<fragment>
Return a 5-tuple: (scheme, netloc, path, query, fragment).
Note that we don't break the components up in smaller bits
(e.g. netloc is a single string) and we don't expand % escapes."""
allow_fragments = bool(allow_fragments)
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key = url, scheme, allow_fragments, type(url), type(scheme)
cached = _parse_cache.get(key, None)
if cached:
return cached
if len(_parse_cache) >= MAX_CACHE_SIZE: # avoid runaway growth
clear_cache()
netloc = query = fragment = ''
i = url.find(':')
if i > 0:
if url[:i] == 'http': # optimize the common case
scheme = url[:i].lower()
url = url[i+1:]
if url[:2] == '//':
netloc, url = _splitnetloc(url, 2)
if allow_fragments and '#' in url:
url, fragment = url.split('#', 1)
if '?' in url:
url, query = url.split('?', 1)
v = SplitResult(scheme, netloc, url, query, fragment)
_parse_cache[key] = v
return v
for c in url[:i]:
if c not in scheme_chars:
break
else:
scheme, url = url[:i].lower(), url[i+1:]
if scheme in uses_netloc and url[:2] == '//':
netloc, url = _splitnetloc(url, 2)
if allow_fragments and scheme in uses_fragment and '#' in url:
url, fragment = url.split('#', 1)
if scheme in uses_query and '?' in url:
url, query = url.split('?', 1)
v = SplitResult(scheme, netloc, url, query, fragment)
_parse_cache[key] = v
return v
def urlunparse((scheme, netloc, url, params, query, fragment)):
"""Put a parsed URL back together again. This may result in a
slightly different, but equivalent URL, if the URL that was parsed
originally had redundant delimiters, e.g. a ? with an empty query
(the draft states that these are equivalent)."""
if params:
url = "%s;%s" % (url, params)
return urlunsplit((scheme, netloc, url, query, fragment))
def urlunsplit((scheme, netloc, url, query, fragment)):
if netloc or (scheme and scheme in uses_netloc and url[:2] != '//'):
if url and url[:1] != '/': url = '/' + url
url = '//' + (netloc or '') + url
if scheme:
url = scheme + ':' + url
if query:
url = url + '?' + query
if fragment:
url = url + '#' + fragment
return url
def urljoin(base, url, allow_fragments=True):
"""Join a base URL and a possibly relative URL to form an absolute
interpretation of the latter."""
if not base:
return url
if not url:
return base
bscheme, bnetloc, bpath, bparams, bquery, bfragment = \
urlparse(base, '', allow_fragments)
scheme, netloc, path, params, query, fragment = \
urlparse(url, bscheme, allow_fragments)
if scheme != bscheme or scheme not in uses_relative:
return url
if scheme in uses_netloc:
if netloc:
return urlunparse((scheme, netloc, path,
params, query, fragment))
netloc = bnetloc
if path[:1] == '/':
return urlunparse((scheme, netloc, path,
params, query, fragment))
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if not (path or params or query):
return urlunparse((scheme, netloc, bpath,
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bparams, bquery, fragment))
segments = bpath.split('/')[:-1] + path.split('/')
# XXX The stuff below is bogus in various ways...
if segments[-1] == '.':
segments[-1] = ''
while '.' in segments:
segments.remove('.')
while 1:
i = 1
n = len(segments) - 1
while i < n:
if (segments[i] == '..'
and segments[i-1] not in ('', '..')):
del segments[i-1:i+1]
break
i = i+1
else:
break
if segments == ['', '..']:
segments[-1] = ''
elif len(segments) >= 2 and segments[-1] == '..':
segments[-2:] = ['']
return urlunparse((scheme, netloc, '/'.join(segments),
params, query, fragment))
def urldefrag(url):
"""Removes any existing fragment from URL.
Returns a tuple of the defragmented URL and the fragment. If
the URL contained no fragments, the second element is the
empty string.
"""
if '#' in url:
s, n, p, a, q, frag = urlparse(url)
defrag = urlunparse((s, n, p, a, q, ''))
return defrag, frag
else:
return url, ''
test_input = """
http://a/b/c/d
g:h = <URL:g:h>
http:g = <URL:http://a/b/c/g>
http: = <URL:http://a/b/c/d>
g = <URL:http://a/b/c/g>
./g = <URL:http://a/b/c/g>
g/ = <URL:http://a/b/c/g/>
/g = <URL:http://a/g>
//g = <URL:http://g>
?y = <URL:http://a/b/c/d?y>
g?y = <URL:http://a/b/c/g?y>
g?y/./x = <URL:http://a/b/c/g?y/./x>
. = <URL:http://a/b/c/>
./ = <URL:http://a/b/c/>
.. = <URL:http://a/b/>
../ = <URL:http://a/b/>
../g = <URL:http://a/b/g>
../.. = <URL:http://a/>
../../g = <URL:http://a/g>
../../../g = <URL:http://a/../g>
./../g = <URL:http://a/b/g>
./g/. = <URL:http://a/b/c/g/>
/./g = <URL:http://a/./g>
g/./h = <URL:http://a/b/c/g/h>
g/../h = <URL:http://a/b/c/h>
http:g = <URL:http://a/b/c/g>
http: = <URL:http://a/b/c/d>
http:?y = <URL:http://a/b/c/d?y>
http:g?y = <URL:http://a/b/c/g?y>
http:g?y/./x = <URL:http://a/b/c/g?y/./x>
"""
def test():
import sys
base = ''
if sys.argv[1:]:
fn = sys.argv[1]
if fn == '-':
fp = sys.stdin
else:
fp = open(fn)
else:
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try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
fp = StringIO(test_input)
while 1:
line = fp.readline()
if not line: break
words = line.split()
if not words:
continue
url = words[0]
parts = urlparse(url)
print '%-10s : %s' % (url, parts)
abs = urljoin(base, url)
if not base:
base = abs
wrapped = '<URL:%s>' % abs
print '%-10s = %s' % (url, wrapped)
if len(words) == 3 and words[1] == '=':
if wrapped != words[2]:
print 'EXPECTED', words[2], '!!!!!!!!!!'
if __name__ == '__main__':
test()