correcting deletions

random12 · random12 · commit 667c9a2224ca · 2023-04-07T14:31:31.000+02:00
diff --git a/Lib/csv.py b/Lib/csv.py
@@ -130,9 +130,12 @@ def __next__(self):
         return d
 
     __class_getitem__ = classmethod(types.GenericAlias)
+
 class DictWriter:
     def __init__(self, f, fieldnames, restval="", extrasaction="raise",
                  dialect="excel", *args, **kwds):
+                 if fieldnames is not None and iter(fieldnames) is fieldnames:
+                    fieldnames = list(fieldnames)
         self.fieldnames = fieldnames    # list of keys for the dict
         self.restval = restval          # for writing short dicts
         if extrasaction.lower() not in ("raise", "ignore"):
@@ -158,6 +161,8 @@ def writerow(self, rowdict):
 
     def writerows(self, rowdicts):
         return self.writer.writerows(map(self._dict_to_list, rowdicts))
+    
+    __class_getitem__ = classmethod(types.GenericAlias)
 
 # Guard Sniffer's type checking against builds that exclude complex()
 try:
