diff options
Diffstat (limited to 'Lib/sets.py')
| -rw-r--r-- | Lib/sets.py | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/Lib/sets.py b/Lib/sets.py index 3897fb9..8808701 100644 --- a/Lib/sets.py +++ b/Lib/sets.py @@ -361,7 +361,10 @@ class Set(BaseSet): # We inherit object.__hash__, so we must deny this explicitly raise TypeError, "Can't hash a Set, only an ImmutableSet." - # In-place union, intersection, differences + # In-place union, intersection, differences. + # Subtle: The xyz_update() functions deliberately return None, + # as do all mutating operations on built-in container types. + # The __xyz__ spellings have to return self, though. def __ior__(self, other): """Update a set with the union of itself and another.""" |