Python - Remove elements at Indices in List

Python – Remove elements at Indices in List

Last Updated : 02 Sep, 2020

Given List, remove all the elements present in indices list.

Input : test_list = [5, 6, 3, 7, 8, 1, 2, 10], idx_list = [2, 4, 5]
Output : [5, 6, 7, 2, 10]
Explanation : 3, 6, and 1 has been removed.
Input : test_list = [5, 6, 3, 7, 8, 1, 2, 10], idx_list = [2]
Output : [5, 6, 7, 8, 1, 2, 10]
Explanation : 3 has been removed.

Method #1 : Using enumerate() + loop

In this, we iterate for all the elements, and if index is present in list, then that index element is omitted from result list.

Python3

# Python3 code to demonstrate working of 
# Remove elements at Indices in List
# Using loop
  
# initializing list
test_list = [5, 6, 3, 7, 8, 1, 2, 10]
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing idx list 
idx_list = [2, 4, 5, 7]
  
res = []
for idx, ele in enumerate(test_list): 
      
    # checking if element not present in index list
    if idx not in idx_list:
        res.append(ele)
  
# printing results
print("Filtered List after removal : " + str(res))

Output

The original list is : [5, 6, 3, 7, 8, 1, 2, 10]
Filtered List after removal : [5, 6, 7, 2]

Method #2 : Using enumerate() + list comprehension

In this, we perform task of iteration using list comprehesion in compact way, rest all method similar to above.

Python3

# Python3 code to demonstrate working of 
# Remove elements at Indices in List
# Using enumerate() + list comprehension
  
# initializing list
test_list = [5, 6, 3, 7, 8, 1, 2, 10]
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing idx list 
idx_list = [2, 4, 5, 7]
  
# one-liner to test for element in index list
res = [ele for idx, ele in enumerate(test_list) if idx not in idx_list]
  
# printing results
print("Filtered List after removal : " + str(res))

Output

The original list is : [5, 6, 3, 7, 8, 1, 2, 10]
Filtered List after removal : [5, 6, 7, 2]

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning – Basic Level Course

My Personal Notes

Related Articles

Python3

Python3