Merge pull request #1 from mdboom/urllib_clarify

Urllib clarify

Author: cgohlke

lib/matplotlib/cbook.py

@@ -18,6 +18,7 @@
 
 major, minor1, minor2, s, tmp = sys.version_info
 
+# Handle the transition from urllib2 in Python 2 to urllib in Python 3
 if major >= 3:
     import types
     import urllib.request, urllib.error, urllib.parse
@@ -26,6 +27,9 @@ def urllib_quote():
     def addinfourl(data, headers, url, code=None):
         return urllib.request.addinfourl(io.BytesIO(data),
                                          headers, url, code)
+    urllib_HTTPSHandler = urllib.request.HTTPSHandler
+    urllib_build_opener = urllib.request.build_opener
+    urllib_URLError = urllib.error.URLError
 else:
     import new
     import urllib2
@@ -34,6 +38,9 @@ def urllib_quote():
     def addinfourl(data, headers, url, code=None):
         return urllib2.addinfourl(io.StringIO(data),
                                   headers, url, code)
+    urllib_HTTPSHandler = urllib2.HTTPSHandler
+    urllib_build_opener = urllib2.build_opener
+    urllib_URLError = urllib2.URLError
 
 import matplotlib
 
@@ -475,18 +482,18 @@ def is_scalar_or_string(val):
     return is_string_like(val) or not iterable(val)
 
 def _get_data_server(cache_dir, baseurl):
-    class ViewVCCachedServer(urllib2.HTTPSHandler):
+    class ViewVCCachedServer(urllib_HTTPSHandler):
         """
-        Urllib2 handler that takes care of caching files.
+        Urllib handler that takes care of caching files.
         The file cache.pck holds the directory of files that have been cached.
         """
         def __init__(self, cache_dir, baseurl):
-            urllib2.HTTPSHandler.__init__(self)
+            urllib_HTTPSHandler.__init__(self)
             self.cache_dir = cache_dir
             self.baseurl = baseurl
             self.read_cache()
             self.remove_stale_files()
-            self.opener = urllib2.build_opener(self)
+            self.opener = urllib_build_opener(self)
 
         def in_cache_dir(self, fn):
             # make sure the datadir exists
@@ -569,7 +576,7 @@ def cache_file(self, url, data, headers):
                                headers.get('Last-Modified'))
             self.write_cache()
 
-        # These urllib2 entry points are used:
+        # These urllib entry points are used:
         # http_request for preprocessing requests
         # http_error_304 for handling 304 Not Modified responses
         # http_response for postprocessing requests
@@ -633,7 +640,7 @@ def get_sample_data(self, fname, asfileobj=True):
             path to the file as a string will be returned.
             """
             # TODO: time out if the connection takes forever
-            # (may not be possible with urllib2 only - spawn a helper process?)
+            # (may not be possible with urllib only - spawn a helper process?)
 
             quote = urllib_quote()
 
@@ -644,7 +651,7 @@ def get_sample_data(self, fname, asfileobj=True):
                                       % url, 'debug')
             try:
                 response = self.opener.open(url)
-            except urllib2.URLError, e:
+            except urllib_URLError as e:
                 # could be a missing network connection
                 error = str(e)