make it works again with python2.5

pipeline/compressors/__init__.py

@@ -11,7 +11,7 @@ except ImportError:
     from django.contrib.staticfiles import finders # noqa
 
 from pipeline.conf import settings
-from pipeline.utils import to_class
+from pipeline.utils import to_class, relpath
 from pipeline.storage import default_storage
 
 MAX_IMAGE_SIZE = 32700
@@ -199,7 +199,7 @@ class Compressor(object):
         """Rewrite paths relative to the output stylesheet path"""
         absolute_path = os.path.join(settings.PIPELINE_ROOT, absolute_path)
         output_path = os.path.join(settings.PIPELINE_ROOT, os.path.dirname(output_filename))
-        return os.path.relpath(absolute_path, output_path)
+        return relpath(absolute_path, output_path)
 
     def read_file(self, path):
         """Read file content in binary mode"""

pipeline/utils.py

+import os
+import sys
 import urllib
 
 from django.utils import importlib
@@ -18,3 +20,54 @@ def filepath_to_uri(path):
     if path is None:
         return path
     return urllib.quote(smart_str(path).replace("\\", "/"), safe="/~!*()'#?")
+
+
+def _relpath_nt(path, start=os.path.curdir):
+    """Return a relative version of a path"""
+    if not path:
+        raise ValueError("no path specified")
+    start_list = os.path.abspath(start).split(os.path.sep)
+    path_list = os.path.abspath(path).split(os.path.sep)
+    if start_list[0].lower() != path_list[0].lower():
+        unc_path, rest = os.path.splitunc(path)
+        unc_start, rest = os.path.splitunc(start)
+        if bool(unc_path) ^ bool(unc_start):
+            raise ValueError("Cannot mix UNC and non-UNC paths (%s and %s)"
+                                                                % (path, start))
+        else:
+            raise ValueError("path is on drive %s, start on drive %s"
+                                                % (path_list[0], start_list[0]))
+    # Work out how much of the filepath is shared by start and path.
+    for i in range(min(len(start_list), len(path_list))):
+        if start_list[i].lower() != path_list[i].lower():
+            break
+    else:
+        i += 1
+
+    rel_list = [os.path.pardir] * (len(start_list) - i) + path_list[i:]
+    if not rel_list:
+        return os.path.curdir
+    return os.path.join(*rel_list)
+
+
+def _relpath_posix(path, start=os.path.curdir):
+    """Return a relative version of a path"""
+    if not path:
+        raise ValueError("no path specified")
+
+    start_list = os.path.abspath(start).split(os.path.sep)
+    path_list = os.path.abspath(path).split(os.path.sep)
+
+    # Work out how much of the filepath is shared by start and path.
+    i = len(os.path.commonprefix([start_list, path_list]))
+
+    rel_list = [os.path.pardir] * (len(start_list) - i) + path_list[i:]
+    if not rel_list:
+        return os.path.curdir
+    return os.path.join(*rel_list)
+
+
+if os.path is sys.modules.get('ntpath'):
+    relpath = _relpath_nt
+else:
+    relpath = _relpath_posix