Python Array List Methods

Python has a set of built-in methods that you can use on lists/arrays.

1) append(elmnt)

Adds an element at the end of the list

fruits = ['apple', 'banana', 'cherry']
fruits.append('orange')
print(fruits) # ['apple', 'banana', 'cherry', 'orange']

2) clear()

Removes all the elements from the list

fruits = ['apple', 'banana', 'cherry', 'orange']
fruits.clear()
print(fruits) # []

3) copy()

Returns a copy of the list

fruits = ["apple", "banana", "cherry"]
x = fruits.copy()
print(x) # ['apple', 'banana', 'cherry']

4) count(value)

Returns the number of elements with the specified value

arr = [1, 4, 2, 9, 7, 8, 9, 3, 1]
x = arr.count(9)
print(x) # 2

5) extend(iterable)

Add the elements of a list (or any iterable), to the end of the current list

fruits = ['apple', 'banana', 'cherry']
cars = ['Ford', 'BMW', 'Volvo']
fruits.extend(cars)
print(fruits) # ['apple', 'banana', 'cherry', 'Ford', 'BMW', 'Volvo']

6) index(elmnt)

Returns the index of the first element with the specified value

numbers = [4, 55, 64, 32, 16, 32]
x = numbers.index(32)
print(x) # 3

7) insert(pos, elmnt)

Adds an element at the specified position

fruits = ['apple', 'banana', 'cherry']
fruits.insert(1, "orange")
print(fruits) # ['apple', 'orange', 'banana', 'cherry']

8) pop(pos)

Removes the element at the specified position

fruits = ['apple', 'banana', 'cherry']
fruits.pop(1)
print(fruits) # ['apple', 'cherry']

9) remove(elmnt)

Removes the first item with the specified value

fruits = ['apple', 'banana', 'cherry']
fruits.remove("banana")
print(fruits) # ['apple', 'cherry']

10) reverse()

Reverses the order of the list

fruits = ['apple', 'banana', 'cherry']
fruits.reverse()
print(fruits) # ['cherry', 'banana', 'apple']

11) sort(reverse=True|False, key=myFunc)

The sort() method sorts the list ascending by default.

cars = ['Ford', 'BMW', 'Volvo']
cars.sort()
print(cars) # ['BMW', 'Ford', 'Volvo']

References:

• Python List, W3Schools
• Python List, GeeksforGeeks