Add two new tools to compare codecs and show differences and to

list all installed codecs.

Tools/unicode/listcodecs.py

@@ -0,0 +1,41 @@
+""" List all available codec modules.
+
+(c) Copyright 2005, Marc-Andre Lemburg (mal@lemburg.com).
+
+    Licensed to PSF under a Contributor Agreement.
+
+"""
+
+import os, codecs, encodings
+
+_debug = 0
+
+def listcodecs(dir):
+    names = []
+    for filename in os.listdir(dir):
+        if filename[-3:] != '.py':
+            continue
+        name = filename[:-3]
+        # Check whether we've found a true codec
+        try:
+            codecs.lookup(name)
+        except LookupError:
+            # Codec not found
+            continue
+        except Exception, reason:
+            # Probably an error from importing the codec; still it's
+            # a valid code name
+            if _debug:
+                print '* problem importing codec %r: %s' % \
+                      (name, reason)
+        names.append(name)
+    return names
+
+
+if __name__ == '__main__':
+    names = listcodecs(encodings.__path__[0])
+    names.sort()
+    print 'all_codecs = ['
+    for name in names:
+        print '    %r,' % name
+    print ']'