Python list pop() is an inbuilt function in Python that removes and returns the last value from the List or the given index value.
Python List pop() Method Syntax
Syntax: list_name.pop(index)
- index (optional) – The value at index is popped out and removed. If the index is not given, then the last element is popped out and removed.
Return: Returns The last value or the given index value from the list.
Exception: Raises IndexError When the index is out of range.
Python List pop() Method Example
Pops and removes the last element from the list using Python.
Python3
l = [ 1 , 2 , 3 , 4 ] print ( "Popped element:" , l.pop()) print ( "List after pop():" , l) |
Output:
Popped element: 4
List after pop(): [1, 2, 3]
Remove Item at specific index from Python List
Pops and removes the 3rd index element from the list.
Python3
list1 = [ 1 , 2 , 3 , 4 , 5 , 6 ] # Pops and removes the 3th index # element from the list print (list1.pop( 3 ), list1) |
Output:
4 [1, 2, 3, 5, 6]
IndexError: pop index out of range
Python3
# Python3 program for error in pop() method list1 = [ 1 , 2 , 3 , 4 , 5 , 6 ] print (list1.pop( 8 )) |
Output:
Traceback (most recent call last):
File "/home/1875538d94d5aecde6edea47b57a2212.py", line 5, in
print(list1.pop(8))
IndexError: pop index out of range
Remove Item at Negative index from Python List
Pops and removes 5 elements from the list.
Python3
list1 = [ 1 , 2 , 3 , 4 , 5 , 6 ] poped_item = list1.pop( - 2 ) print ( "New list" , list1) print ( "Poped Item" , poped_item) |
Output:
New list [1, 2, 3, 4, 6]
Poped Item 5
Practical Example
A list of the fruit contains fruit_name and property saying its fruit. Another list consume has two items juice and eat. With the help of pop() and append() we can do something interesting.
Python3
fruit = [[ 'Orange' , 'Fruit' ],[ 'Banana' , 'Fruit' ], [ 'Mango' , 'Fruit' ]] consume = [ 'Juice' , 'Eat' ] possible = [] # Iterating item in list fruit for item in fruit : # Iterating use in list consume for use in consume : item.append(use) possible.append(item[:]) item.pop( - 1 ) print (possible) |
Output:
[['Orange', 'Fruit', 'Juice'], ['Orange', 'Fruit', 'Eat'],
['Banana', 'Fruit', 'Juice'], ['Banana', 'Fruit', 'Eat'],
['Mango', 'Fruit', 'Juice'], ['Mango', 'Fruit', 'Eat']]
Time Complexity :
The complexity of all the above examples is constant O(1) in both average and amortized case