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Diffstat (limited to 'immutables/map.py')
| -rw-r--r-- | immutables/map.py | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/immutables/map.py b/immutables/map.py index 7b230dd..4c5cd49 100644 --- a/immutables/map.py +++ b/immutables/map.py @@ -719,6 +719,9 @@ class MapMutation: return True def update(self, col=None, **kw): + if self.__mutid == 0: + raise ValueError('mutation {!r} has been finished'.format(self)) + it = None if col is not None: if hasattr(col, 'items'): |