Issue 33879: Item assignment in tuple mutates list despite throwing error (original) (raw)

Seems like a bug.

>>> a = (1, [1])
>>> a[1] += [2]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'tuple' object does not support item assignment
>>> a
(1, [1, 2])