Python add to List

Filed Under: Python
Python Add To List

There are four ways to add elements to a List in Python.

  1. append(): append the object to the end of the list.
  2. insert(): inserts the object before the given index.
  3. extend(): extends the list by appending elements from the iterable.
  4. List Concatenation: We can use + operator to concatenate multiple lists and create a new list.

Python add to List

We can add an element to the end of the list or at any given index. There are ways to add elements from an iterable to the list. We can also use + operator to concatenate multiple lists to create a new list.

1. append(): add to the end of the list


fruits = ["Apple", "Banana"]

# 1. append()
print(f'Current Fruits List {fruits}')

f = input("Please enter a fruit name:\n")
fruits.append(f)

print(f'Updated Fruits List {fruits}')

Output:


Current Fruits List ['Apple', 'Banana']
Please enter a fruit name:
Orange
Updated Fruits List ['Apple', 'Banana', 'Orange']

2. insert(): add element at the given index of the list

This function is useful to add element at the specified index of the list.


num_list = [1, 2, 3, 4, 5]

print(f'Current Numbers List {num_list}')

num = int(input("Please enter a number to add to list:\n"))

index = int(input(f'Please enter the index between 0 and {len(num_list) - 1} to add the number:\n'))

num_list.insert(index, num)

print(f'Updated Numbers List {num_list}')

Output:


Current Numbers List [1, 2, 3, 4, 5]
Please enter a number to add to list:
20
Please enter the index between 0 and 4 to add the number:
2
Updated Numbers List [1, 2, 20, 3, 4, 5]

3. extend(): append iterable elements to the list

This function is useful to append elements from an iterable to the end of the list.


list_num = []
list_num.extend([1, 2])  # extending list elements
print(list_num)
list_num.extend((3, 4))  # extending tuple elements
print(list_num)
list_num.extend("ABC")  # extending string elements
print(list_num)

Output:


[1, 2]
[1, 2, 3, 4]
[1, 2, 3, 4, 'A', 'B', 'C']

4. List Concatenation: concatenate multiple lists using + operator

If you have to concatenate multiple lists, you can use the “+” operator. This will create a new list and the original lists will remain unchanged.


evens = [2, 4, 6]
odds = [1, 3, 5]

nums = odds + evens
print(nums)  # [1, 3, 5, 2, 4, 6]

References:

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