Remove Key from Dictionary List - Python

Last Updated : 28 Jan, 2025

We are given a list of dictionaries and our task is to remove a specific key from each dictionary in the list. For example, if we have the following list: li = [{'Gfg': 1, 'id': 2, 'best': 8}, {'Gfg': 4, 'id': 4, 'best': 10}, {'Gfg': 4, 'id': 8, 'best': 11}] and the key to remove is "id" then the resulting list will be [{'Gfg': 1, 'best': 8}, {'Gfg': 4, 'best': 10}, {'Gfg': 4, 'best': 11}].

Using loop and del

We can iterate through the list of dictionaries and use the del keyword to remove the specified key from each dictionary and this approach directly modifies the original list.

Python

li = [{'Gfg': 1, 'id': 2, 'best': 8},        {'Gfg': 4, 'id': 4, 'best': 10},        {'Gfg': 4, 'id': 8, 'best': 11}]  del_key = 'id'  # Removing the key using loop + del for item in li:     if del_key in item:         del item[del_key]  print(li)

Output

[{'Gfg': 1, 'best': 8}, {'Gfg': 4, 'best': 10}, {'Gfg': 4, 'best': 11}]

Explanation: Each dictionary in the list is checked for the key and if it exists then the del statement removes the key-value pair.

Using pop()

We use the pop() method to remove the key from each dictionary in the list and if the key does not exist then we handle it by specifying a default value.

Python

li = [{'Gfg': 1, 'id': 2, 'best': 8},        {'Gfg': 4, 'id': 4, 'best': 10},        {'Gfg': 4, 'id': 8, 'best': 11}]  del_key = 'id'  # Removing the key using pop() for item in li:     item.pop(del_key, None)  print(li)

Output

[{'Gfg': 1, 'best': 8}, {'Gfg': 4, 'best': 10}, {'Gfg': 4, 'best': 11}]

Explanation: pop() method removes the key-value pair if the key exists in the dictionary and if the key does not exist then the default value None prevents a KeyError.

Using Dictionary Comprehension

This method involves reconstructing each dictionary in the list excluding the specified key using a dictionary comprehension.

Python

li = [{'Gfg': 1, 'id': 2, 'best': 8},        {'Gfg': 4, 'id': 4, 'best': 10},        {'Gfg': 4, 'id': 8, 'best': 11}]  del_key = 'id'  # Removing the key using dictionary comprehension li = [{k: v for k, v in item.items() if k != del_key} for item in li]  print(li)

Output

[{'Gfg': 1, 'best': 8}, {'Gfg': 4, 'best': 10}, {'Gfg': 4, 'best': 11}]

Explanation: dictionary comprehension {k: v for k, v in item.items() if k != del_key} creates a new dictionary excluding the key del_key.

Using map() and a Lambda Function

In this method we use map() function combined with a lambda function to remove the specified key from each dictionary in the list.

Python

li = [{'Gfg': 1, 'id': 2, 'best': 8},        {'Gfg': 4, 'id': 4, 'best': 10},        {'Gfg': 4, 'id': 8, 'best': 11}]  del_key = 'id'  # Removing the key using map() and a lambda function li = list(map(lambda item: {k: v for k, v in item.items() if k != del_key}, li))  print(li)

Output

[{'Gfg': 1, 'best': 8}, {'Gfg': 4, 'best': 10}, {'Gfg': 4, 'best': 11}]

Explanation: map() function applies the lambda function to each item in the list and the lambda function {k: v for k, v in item.items() if k != del_key} removes the specified key from each dictionary.