["python","list","append","nonetype"]
Why does append() always return None in Python?

list = [1, 2, 3] print(list.append(4)) ## WRONG, print does not work, append() returns None ## RIGHT: list.append(4) print(list) ## [1, 2, 3, 4] I'm learning Python and I'm not sure if this problem is specific to the language and how append is implemented in Python.
append is a mutating (destructive) operation (it modifies the list in place instead of of returning a new list). The idiomatic way to do the non-destructive equivalent of append would be >>> l = [1,2,3] >>> l + [4] [1,2,3,4] >>> l [1,2,3] to answer your question, my guess is that if append returned the newly modified list, users might think that it was non-destructive, ie they might write code like m = l.append("a") n = l.append("b") and expect n to be [1,2,3,"b"]