20004: Note that the setter in csv.DictReader is broken.
This is a comment in the code because only someone reading the code would try
setting fieldnames to None in the first place...
diff --git a/Lib/csv.py b/Lib/csv.py
index fc080cc..c155ada 100644
--- a/Lib/csv.py
+++ b/Lib/csv.py
@@ -93,6 +93,10 @@
self.line_num = self.reader.line_num
return self._fieldnames
+ # Issue 20004: Because DictReader is a classic class, this setter is
+ # ignored. At this point in 2.7's lifecycle, it is too late to change the
+ # base class for fear of breaking working code. If you want to change
+ # fieldnames without overwriting the getter, set _fieldnames directly.
@fieldnames.setter
def fieldnames(self, value):
self._fieldnames = value