diff --git a/scripts/logformat.py b/scripts/logformat.py
--- a/scripts/logformat.py
+++ b/scripts/logformat.py
@@ -3,13 +3,6 @@
 import re
 import sys
 
-if len(sys.argv) < 2:
-    print 'Cleanup of superfluous % formatting of log statements.'
-    print 'Usage:'
-    print '''  hg revert `hg loc '*.py'|grep -v logformat.py` && scripts/logformat.py `hg loc '*.py'` && hg diff'''
-    raise SystemExit(1)
-
-
 logre = r'''
 (log\.(?:error|info|warning|debug)
 [(][ \n]*
@@ -19,6 +12,8 @@ logre = r'''
 [ \n]*[)]
 )
 '''
+
+
 res = [
     # handle % () - keeping spaces around the old %
     (re.compile(logre % r'''("[^"]*"|'[^']*')   ([\n ]*) %  ([\n ]*) \( ( (?:[^()]|\n)* (?: \( (?:[^()]|\n)* \) (?:[^()]|\n)* )* ) \) ''', flags=re.MULTILINE|re.VERBOSE), r'\1\2,\3\4\5\6'),
@@ -32,8 +27,20 @@ res = [
     (re.compile(logre % r'''("[^"]*"|'[^']*') ,       () (   [\n ]*)    ( (?:[^()]|\n)* (?: \( (?:[^()]|\n)* \) (?:[^()]|\n)* )* [^(), \n] ) [ ,]*''', flags=re.MULTILINE|re.VERBOSE), r'\1\2,\3\4\5\6'),
     ]
 
-for f in sys.argv[1:]:
+
+def rewrite(f):
     s = open(f).read()
     for r, t in res:
         s = r.sub(t, s)
     open(f, 'w').write(s)
+
+
+if __name__ == '__main__':
+    if len(sys.argv) < 2:
+        print 'Cleanup of superfluous % formatting of log statements.'
+        print 'Usage:'
+        print '''  hg revert `hg loc '*.py'|grep -v logformat.py` && scripts/logformat.py `hg loc '*.py'` && hg diff'''
+        raise SystemExit(1)
+
+    for f in sys.argv[1:]:
+        rewrite(f)