unsupported-assignment-operation / E1137

Message emitted:

%r does not support item assignment

Description:

Emitted when an object does not support item assignment (i.e. doesn't define __setitem__ method).

Problematic code:

def pick_fruits(fruits):
    for fruit in fruits:
        print(fruit)


pick_fruits(["apple"])[0] = "orange"  # [unsupported-assignment-operation]

Correct code:

def pick_fruits(fruits):
    for fruit in fruits:
        print(fruit)

    return []


pick_fruits(["apple"])[0] = "orange"

Created by the typecheck checker.