New tty/pty modules by Steen; new urlparser.

Lib/urlparse.py

@@ -0,0 +1,195 @@
+# Parse (absolute and relative) URLs according to latest internet draft:
+
+# Uniform Resource Identifiers Working Group                  R. Fielding
+# INTERNET-DRAFT                                                UC Irvine
+# Expires February 24, 1995                               August 24, 1994
+#
+#                   Relative Uniform Resource Locators
+#                  <draft-ietf-uri-relative-url-00.txt>
+
+# Standard/builtin Python modules
+import string
+
+# A classification of schemes ('' means apply by default)
+uses_relative = ['ftp', 'http', 'gopher', 'nntp', 'wais', 'file',
+		 'prospero', '']
+uses_netloc = ['ftp', 'http', 'gopher', 'nntp', 'telnet', 'wais',
+	       'file', 'prospero', '']
+non_hierarchical = ['gopher', 'mailto', 'news', 'telnet', 'wais']
+uses_params = ['ftp', 'prospero', '']
+uses_query = ['http', 'wais', '']
+uses_fragment = ['ftp', 'http', 'gopher', 'news', 'nntp', 'wais',
+		 'file', 'prospero', '']
+
+# Characters valid in scheme names
+scheme_chars = string.letters + string.digits + '+-.'
+
+# 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.
+def urlparse(url, scheme = '', allow_framents = 1):
+	netloc = ''
+	path = ''
+	params = ''
+	query = ''
+	fragment = ''
+	i = string.find(url, ':')
+	if i > 0:
+		for c in url[:i]:
+			if c not in scheme_chars:
+				break
+		else:
+			scheme, url = string.lower(url[:i]), url[i+1:]
+	if scheme in uses_netloc:
+		if url[:2] == '//':
+			i = string.find(url, '/', 2)
+			if i < 0:
+				i = len(url)
+			netloc, url = url[2:i], url[i:]
+	if allow_framents and scheme in uses_fragment:
+		i = string.rfind(url, '#')
+		if i >= 0:
+			url, fragment = url[:i], url[i+1:]
+	if scheme in uses_query:
+		i = string.find(url, '?')
+		if i >= 0:
+			url, query = url[:i], url[i+1:]
+	if scheme in uses_params:
+		i = string.find(url, ';')
+		if i >= 0:
+			url, params = url[:i], url[i+1:]
+	return 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).
+def urlunparse((scheme, netloc, url, params, query, fragment)):
+	if netloc:
+		url = '//' + netloc + url
+	if scheme:
+		url = scheme + ':' + url
+	if params:
+		url = url + ';' + params
+	if query:
+		url = url + '?' + query
+	if fragment:
+		url = url + '#' + fragment
+	return url
+
+# Join a base URL and a possibly relative URL to form an absolute
+# interpretation of the latter.
+def urljoin(base, url, allow_framents = 1):
+	if not base:
+		return url
+	bscheme, bnetloc, bpath, bparams, bquery, bfragment = \
+		  urlparse(base, '', allow_framents)
+	scheme, netloc, path, params, query, fragment = \
+		urlparse(url, bscheme, allow_framents)
+	if scheme != bscheme or scheme not in uses_relative:
+		return urlunparse((scheme, netloc, path,
+				   params, query, fragment))
+	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))
+	if not path:
+		path = bpath
+		if not query:
+			query = bquery
+		return urlunparse((scheme, netloc, path,
+				   params, query, fragment))
+	i = string.rfind(bpath, '/')
+	if i < 0:
+		i = len(bpath)
+	path = bpath[:i] + '/' + path
+	segments = string.splitfields(path, '/')
+	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]:
+				del segments[i-1:i+1]
+				break
+			i = i+1
+		else:
+			break
+	if len(segments) >= 2 and segments[-1] == '..':
+		segments[-2:] = ['']
+	path = string.joinfields(segments, '/')
+	return urlunparse((scheme, netloc, path,
+			   params, query, fragment))
+
+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>
+"""
+
+def test():
+	import sys
+	base = ''
+	if sys.argv[1:]:
+		fn = sys.argv[1]
+		if fn == '-':
+			fp = sys.stdin
+		else:
+			fp = open(fn)
+	else:
+		import StringIO
+		fp = StringIO.StringIO(test_input)
+	while 1:
+		line = fp.readline()
+		if not line: break
+		words = string.split(line)
+		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()