python: Complete all files only if -c is before current word

completions/python

@@ -36,7 +36,7 @@ _python()
 
     # if '-c' is already given, complete all kind of files.
     local i
-    for (( i=0; i < ${#words[@]}-1; i++ )); do
+    for (( i=0; i < $cword; i++ )); do
         if [[ ${words[i]} == -c ]]; then
             _filedir
         fi