Move the string parsing inside the try body.

It seems that _formatter_parser raises ValueError on PyPy,
while on CPython it raises the error only when iterating
the result.

1 files changed, 1 insertions, 1 deletions

diff --git a/checkers/strings.py b/checkers/strings.py
index 318393d..5eb151f 100644
--- a/checkers/strings.py
+++ b/checkers/strings.py
@@ -145,8 +145,8 @@ def collect_string_fields(format_string):
     """
 
     formatter = string.Formatter()
-    parseiterator = formatter.parse(format_string)
     try:
+        parseiterator = formatter.parse(format_string)
         for result in parseiterator:
             if all(item is None for item in result[1:]):
                 # not a replacement format