When is del useful in Python?
Firstly, you can del other things besides local variables
del list_itemdel dictionary["alpha"]
Both of which should be clearly useful. Secondly, using
del on a local variable makes the intent clearer. Compare:
foo = None
I know in the case of
del foo that the intent is to remove the variable from scope. It's not clear that
foo = None is doing that. If somebody just assigned
foo = None I might think it was dead code. But I instantly know what somebody who codes
del foo was trying to do.
There's this part of what
del does (from the Python Language Reference):
Deletion of a name removes the binding of that name from the local or global namespace
None to a name does not remove the binding of the name from the namespace.
(I suppose there could be some debate about whether removing a name binding is actually useful, but that's another question.)