Newbie lists problem

[buran]

empty_list = []
first_var = 1

filled_list = empty_list.append(first_var) # here it will append to empty_list and append returns None which is assigned to filled_list
print(filled_list)
print(empty_list)

Output:
None
[1]
>>>

So your code is equivalent to

empty_list = []
first_var = 1
empty_list.append(first_var)
filled_list = None
print(filled_list)