Here is the decompilation of the listcomp
[x for x in range(5)]
:
RESUME 0
BUILD_LIST
LOAD_FAST
FOR_ITER 4
STORE_FAST (x)
LOAD_FAST (x)
LIST_APPEND
JUMP_BACKWARDS 5
RETURN_VALUE
As you can see from the third last instruction, a listcomp does append individual elements to the list. What it doesn’t need to do is call a method to do so (let alone lookup the corresponding method).