Concept: List methods & operators

A list contains multiple methods that can be used to manipulate the list. Some of the most commonly used methods are:

• append(): Adds an item to the end of the list.

  users = ["Alice", "Bob"]
  users.append("Eve")
  print(users) # Output: ["Alice", "Bob", "Eve"]

• extend(): Extends the list by appending all the items from another iterable (e.g., another list).

  users = ["Alice", "Bob"]
  new_users = ["Eve", "Frank"]
  users.extend(new_users)
  print(users) # Output: ["Alice", "Bob", "Eve", "Frank"]

• insert(): Inserts an item at a specified index in the list.

  users = ["Alice", "Bob"]
  users.insert(1, "Eve")
  print(users) # Output: ["Alice", "Eve", "Bob"]

• remove(): Removes the first occurrence of a specified item from the list.

  users = ["Alice", "Bob", "Eve"]
  users.remove("Eve")
  print(users) # Output: ["Alice", "Bob"]

• pop(): Removes and returns the item at a specified index (or the last item if no index is specified).

  users = ["Alice", "Bob", "Eve"]
  removed_user = users.pop(1)
  print(users) # Output: ["Alice", "Eve"]
  print(removed_user) # Output: "Bob"

• clear(): Removes all items from the list.

  users = ["Alice", "Bob", "Eve"]
  users.clear()
  print(users) # Output: []

• len(): Returns the number of items in the list.

  users = ["Alice", "Bob", "Eve"]
  length = len(users)
  print(length) # Output: 3

• index(): Returns the index of the first occurrence of a specified item in the list.

  users = ["Alice", "Bob", "Eve"]
  index_eve = users.index("Eve")
  print(index_eve) # Output: 2

• reverse(): Reverses the order of items in the list.

  users = ["Alice", "Bob", "Eve"]
  users.reverse()
  print(users) # Output: ["Eve", "Bob", "Alice"]

• count(): Returns the number of occurrences of a specified item in the list.

  users = ["Alice", "Bob", "Eve", "Alice"]
  count_alice = users.count("Alice")
  print(count_alice) # Output: 2

There are also operators that can be used with lists:

Operator	Description	Example	Result
+	Concatenation	["a", "b"] + ["c", "d"]	["a", "b", "c", "d"]
*	Repetition	["a", "b"] * 2	["a", "b", "a", "b"]
<	Less than	["a", "b"] < ["c", "d"]	True
>	Greater than	["a", "b"] > ["c", "d"]	False
==	Equal to	["a", "b"] == ["a", "b"]	True
!=	Not equal to	["a", "b"] != ["c", "d"]	True
in	Membership	"a" in ["a", "b"]	True
not in	Not membership	"c" not in ["a", "b"]	True