Why does the append method return None with my list? [duplicate]

Answer 1

I try to explain in the easiest way: With:

a.append(5)

you are calling the function that adds something (in this case 5) to a

With:

a = a.append(5)

you are saying that a is equal the result of the funcion .append(). But append just modifies an existing list, it does not returns anything, and it does not, as you thought, return a new list with the element appended.

Answer 2

Because you're assigning an output to the act of appending which has no output, so instead of:

a=a.append(5)

you just want

a.append(5)

Answer 3

This just indicates that the "append" method does not return anything. It only modifies the existing list. It does not return an updated list.

Don't bother doing a = a.append(4). If you just want to add an entry to the list, do a.append(4) to modify a.