# HG changeset patch
# User aronacher
# Date 1213732742 0
# Node ID 2b74cff3c612e49b850a91d3f2c25dfed188ae63
# Parent  249aab27c4b32799741b89f8555bfcb741a12c2a
Fixed a small bug in the python format string checker that caused the wrong exception to be thrown.

diff --git a/babel/messages/checkers.py b/babel/messages/checkers.py
--- a/babel/messages/checkers.py
+++ b/babel/messages/checkers.py
@@ -44,6 +44,7 @@
 
 
 def python_format(catalog, message):
+    """Verify the format string placeholders in the translation."""
     if 'python-format' not in message.flags:
         return
     msgids = message.id
@@ -114,8 +115,8 @@
                 positional = name is None
             else:
                 if (name is None) != positional:
-                    raise ValueError('format string mixes positional '
-                                     'and named placeholders')
+                    raise TranslationError('format string mixes positional '
+                                           'and named placeholders')
         return bool(positional)
 
     a, b = map(_parse, (format, alternative))