Contents of /bunnyblog/modules/urlpath.py

Tue Jan 29 14:32:01 2008 UTC

Re-import of repository after repository database corruption.

1	# urlpath.py
2
3	# 0.1.0
4	# 2005/08/20
5
6	# Functions that handle url paths.
7	# Part of Pythonutils
8	# http://www.voidspace.org.uk/python/pythonutils.html
9
10	# Copyright Michael Foord, 2004 & 2005.
11	# Released subject to the BSD License
12	# Please see http://www.voidspace.org.uk/documents/BSD-LICENSE.txt
13
14	# For information about bugfixes, updates and support, please join the
15	# Pythonutils mailing list.
16	# http://voidspace.org.uk/mailman/listinfo/pythonutils_voidspace.org.uk
17	# Comments, suggestions and bug reports welcome.
18	# Scripts maintained at http://www.voidspace.org.uk/python/index.shtml
19	# E-mail [email protected]
20
21	import posixpath
22	import os
23	from urllib import url2pathname, pathname2url
24
25	__all__ = [
26	'nativejoin',
27	'pathjoin',
28	'relpathto',
29	'tslash',
30	'relpath'
31	]
32
33	def pathjoin(base, *paths):
34	"""
35	Join paths to a base, observing pardir.
36
37	If base doesn't end with '/' we assume it's a file rather than a directory.
38	(so we get rid of it)
39	"""
40	# XXXX will posixpath.join do all this anyway?
41	if base and not base.endswith('/'):
42	# get rid of the filename
43	base = '/'.join(base.split('/')[:-1])
44	base = tslash(base)
45	path = (base,) + paths
46	return posixpath.normpath(posixpath.join(*path))
47
48	def nativejoin(base, path):
49	"""
50	Joins two paths - returning a native file path.
51
52	Given a base path and a relative location, (in posix format)
53	return a file path in a (relatively) OS native way.
54	"""
55	return url2pathname(pathjoin(base, path))
56
57	def relpathto(thisdir, origin, dest):
58	"""
59	Given two paths relative to a directory, work out a path from origin
60	to destination.
61
62	Assumes UNIX/URL type relative paths.
63	If origin doesn't end with '/' we assume it's a file rather than a
64	directory.
65
66	If the same paths are passed in :
67	if the path ends with ('/') then we return ''
68	else we return the last part of the path (presumably a filename)
69
70	If thisdir doesn't start with '/' then we add one
71	(this makes the top level of thisdir our root directory)
72	"""
73	orig_thisdir = thisdir
74	if not thisdir.startswith('/'):
75	thisdir = '/' + thisdir
76	orig_abs = posixpath.normpath(posixpath.join(thisdir, origin))
77	dest_abs = posixpath.normpath(posixpath.join(thisdir, dest))
78	if origin.endswith('/') and not orig_abs.endswith('/'):
79	orig_abs = orig_abs + '/'
80	if dest.endswith('/') and not dest_abs.endswith('/'):
81	dest_abs = dest_abs + '/'
82	# print orig_abs, dest_abs
83	#
84	# if the first item is a filename, we want to get rid of it
85	orig_list = orig_abs.split('/')[:-1]
86	dest_list = dest_abs.split('/')
87	# print orig_list, dest_list
88
89	if orig_list[0] != dest_list[0]:
90	# can't get here from there
91	# XXXX raise exception?
92	return dest
93	#
94	# find the location where the two paths start to differ.
95	i = 0
96	for start_seg, dest_seg in zip(orig_list, dest_list):
97	if start_seg != dest_seg:
98	break
99	i += 1
100	#
101	# now i is the point where the two paths diverge;
102	# need a certain number of "os.pardir"s to work up
103	# from the origin to the point of divergence.
104	segments = ['..'] * (len(orig_list) - i)
105	# need to add the diverging part of dest_list.
106	segments += dest_list[i:]
107	if len(segments) == 0:
108	# if they happen to be identical paths
109	# identical directories
110	if dest.endswith('/'):
111	return ''
112	# just the filename - the last part of dest
113	return dest_list[-1]
114	else:
115	return '/'.join(segments)
116
117	def relpath(origin, dest):
118	"""Given two absolute paths, work out a path from origin to destination.
119
120	Assumes UNIX/URL type relative paths.
121	If origin doesn't end with '/' we assume it's a file rather than
122	a directory.
123
124	If the same paths are passed in :
125	if the path ends with ('/') then we return ''
126	else we return the last part of the path (presumably a filename)
127
128	If origin or dest don't start with '/' then we add it.
129
130	We are assuming relative paths on the same device
131	(i.e. same top level directory)
132	"""
133	if not origin.startswith('/'):
134	origin = '/' + origin
135	if not dest.startswith('/'):
136	dest = '/' + dest
137	#
138	# if the first item is a filename, we want to get rid of it
139	orig_list = origin.split('/')[:-1]
140	dest_list = dest.split('/')
141	#
142	# find the location where the two paths start to differ.
143	i = 0
144	for start_seg, dest_seg in zip(orig_list, dest_list):
145	if start_seg != dest_seg:
146	break
147	i += 1
148
149	# now i is the point where the two paths diverge.
150	# need a certain number of "os.pardir"s to work up
151	# from the origin to the point of divergence.
152	segments = ['..'] * (len(orig_list) - i)
153	# need to add the diverging part of dest_list.
154	segments += dest_list[i:]
155	if len(segments) == 0:
156	# if they happen to be identical paths
157	# identical directories
158	if dest.endswith('/'):
159	return ''
160	# just the filename - the last part of dest
161	return dest_list[-1]
162	else:
163	return '/'.join(segments)
164
165	def tslash(apath):
166	"""Add a trailing slash to a path if it needs one.
167
168	Doesn't use os.sep because you end up jiggered on windoze - when you
169	want separators for URLs.
170	"""
171	if (apath and
172	apath != '.' and
173	not apath.endswith('/') and
174	not apath.endswith('\\')):
175	return apath + '/'
176	else:
177	return apath
178
179	##############################################
180
181	def testJoin():
182	thelist = [
183	('/', 'fish.html'),
184	('/dir/dir/', '../file'),
185	('dir/dir/', '../file'),
186	('dir/dir/', '../../file'),
187	('dir/dir/', '../../../file'),
188	('/dir/dir/', '../notherdir/file'),
189	('/dir/dir/', '../../notherdir/file'),
190	('dir/dir/', '../../notherdir/file'),
191	('dir/dir/', '../../../notherdir/file'),
192	('', '../path'),
193	]
194	for entry in thelist:
195	print entry, ' :: ', pathjoin(*entry)
196	print entry, ' :: ', nativejoin(*entry)
197	print '\n'
198
199	def testRelpathto():
200	thedir = '//toplevel/dirone/dirtwo/dirthree'
201	thelist = [
202	('file1.html', 'file2.html'),
203	('file1.html', '../file2.html'),
204	('../file1.html', '../file2.html'),
205	('../file1.html', 'file2.html'),
206	('../fish1/fish2/', '../../sub1/sub2/'),
207	('../fish1/fish2/', 'sub1/sub2'),
208	('../../../fish1/fish2/', 'sub1/sub2/'),
209	('../../../fish1/fish2/', 'sub1/sub2/file1.html'),
210	]
211	for orig, dest in thelist:
212	print '(%s, %s) : ' % (orig, dest), relpathto(thedir, orig, dest)
213
214	def testRelpathto2():
215	thedir = 'section3/'
216	thelist = [
217	('../archive/strangeindex1.html', 'article2.html'),
218	]
219	for orig, dest in thelist:
220	answer = relpathto(thedir, orig, dest)
221	print '(%s, %s) : ' % (orig, dest), answer
222
223	def testRelpath():
224	thelist = [
225	('/hello/fish/', 'bungles'),
226	]
227	for orig, dest in thelist:
228	answer = relpath(orig, dest)
229	print '(%s, %s) : ' % (orig, dest), answer
230
231
232	if __name__ == '__main__':
233	testJoin()
234	testRelpathto()
235	testRelpath()
236	# testRelpathto2()
237
238	"""
239	TODO
240	====
241
242	More comprehensive tests.
243
244	CHANGELOG
245	2005/07/31
246	Can now pass mulitple args to ``pathjoin``.
247	Finalised as version 0.1.0
248
249	2005/06/18
250	Changes by Nicola Larosa
251	Code cleanup
252	lines shortened
253	comments on line above code
254	empty comments in empty lines
255
256	2005/05/28
257	Added relpath to __all__
258
259
260	TODO
261	Move into pythonutils
262	relpathto could call relpath (and so be shorter)
263	nativejoin could accept multiple paths
264	Could tslash be more elegant ?
265	"""
266

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