Put some code back.

Author: makeajourney

pandas/io/parsers.py

@@ -2278,11 +2278,10 @@ def __init__(self, f, **kwds):
             raise ValueError('Only length-1 decimal markers supported')
 
         if self.thousands is None:
-            self.nonnum = re.compile(
-                r'[^-^0-9^{decimal}]+'.format(decimal=self.decimal))
+            self.nonnum = re.compile('[^-^0-9^%s]+' % self.decimal)
         else:
-            self.nonnum = re.compile(r'[^-^0-9^{thousands}^{decimal}]+'.format(
-                thousands=self.thousands, decimal=self.decimal))
+            self.nonnum = re.compile('[^-^0-9^%s^%s]+' % (self.thousands, 
+                                                          self.decimal))
 
     def _set_no_thousands_columns(self):
         # Create a set of column ids that are not to be stripped of thousands