<s>[INST] append vs. extend What's the difference between the list methods append() and extend()?
 [/INST] append: Appends object at end.
x = [1, 2, 3]
x.append([4, 5])
print (x)

gives you: [1, 2, 3, [4, 5]]

extend: Extends list by appending elements from the iterable.
x = [1, 2, 3]
x.extend([4, 5])
print (x)

gives you: [1, 2, 3, 4, 5]
 </s>