What does an if statement evaluate a list to?

Question

What does an if statement on a list in python evaluate to? I remember reading somewhere that if you do it on an empty list if evaluates to false and otherwise it evaluates to True. Is there any reason to check for the list length also?

For example:

list = [10]*10

if list:
    print("First check)

if list and len(list):
    print("Second check")

What do the above two checks look at? They both evaluate to true.

Answer 1

if list: means list is not empty and in your code it contains 10 elements. So, the condition is always going to be true. Also, length of your list is 10. so, second condition is also true. so, no difference..

Answer 2

The definite answer is in the Python documentation:

Only the empty list is false, even a list containing just one Noneis true. So the length test adds nothing to result.

Answer 3

An empty list is a false-y. There's no need to explicitly check the length too.

Answer 4

if list means:

1. if list != []
2. if list != None