Python List Methods

Adding Items

append() adds one item to the end of a list. insert() places an item at a specific index, shifting the rest to the right. extend() adds every item from another iterable, one by one.

nums = [1, 2, 3]
nums.append(4)          # [1, 2, 3, 4]
nums.insert(0, 0)       # [0, 1, 2, 3, 4]
nums.extend([5, 6])     # [0, 1, 2, 3, 4, 5, 6]
print(nums)

Removing Items

remove() deletes the first matching value. pop() removes and returns an item by index (defaults to the last item) — useful when you need the removed value, for example when building a stack.

nums = [0, 1, 2, 3]
nums.remove(1)   # removes value 1 -> [0, 2, 3]
last = nums.pop()       # removes and returns 3
first = nums.pop(0)     # removes and returns 0
print(nums, last, first)

Sorting and Reversing

sort() reorders a list in place (ascending by default; pass reverse=True for descending). reverse() simply flips the current order. Both change the original list rather than returning a new one.

scores = [88, 45, 92, 60]
scores.sort()             # [45, 60, 88, 92]
scores.sort(reverse=True) # [92, 88, 60, 45]
scores.reverse()          # flips current order
print(scores)

Searching and Counting

count() tells you how many times a value appears, and index() finds the position of the first match — both are handy when validating user input or analysing data inside functions.

letters = ["a", "b", "a", "c", "a"]
print(letters.count("a"))  # 3
print(letters.index("c"))  # 3

Quick-Reference Table