Python - Remove Tuples from the List having every element as None

Last Updated : 15 May, 2023

Given a Tuple list, remove all tuples with all None values.

Input : test_list = [(None, 2), (None, None), (3, 4), (12, 3), (None, )]  Output : [(None, 2), (3, 4), (12, 3)]  Explanation : All None tuples are removed.

Input : test_list = [(None, None), (None, None), (3, 4), (12, 3), (None, )]  Output : [(3, 4), (12, 3)]  Explanation : All None tuples are removed.

Method #1 : Using all() + list comprehension

In this, we use all() to check for all None values for discarding and list comprehension does task of iteration.

Python3

# Python3 code to demonstrate working of  # Remove None Tuples from List # Using all() + list comprehension  # initializing list test_list = [(None, 2), (None, None), (3, 4), (12, 3), (None, )]  # printing original list print("The original list is : " + str(test_list))  # negating result for discarding all None Tuples res = [sub for sub in test_list if not all(ele == None for ele in sub)]  # printing result  print("Removed None Tuples : " + str(res))

Output

The original list is : [(None, 2), (None, None), (3, 4), (12, 3), (None,)] Removed None Tuples : [(None, 2), (3, 4), (12, 3)]

Time complexity: O(n), where n is the length of the input list.
Auxiliary space: O(m), where m is the number of non-None tuples in the input list.

Method #2 : Using filter() + lambda + all()

In this method, task of filtering None tuples is done using filter() and lambda function to provide None checking functionality using all().

Python3

# Python3 code to demonstrate working of  # Remove None Tuples from List # Using filter() + lambda + all()  # initializing list test_list = [(None, 2), (None, None), (3, 4), (12, 3), (None, )]  # printing original list print("The original list is : " + str(test_list))  # filter() + lambda to drive logic of discarding tuples res = list(filter(lambda sub : not all(ele == None for ele in sub), test_list))  # printing result  print("Removed None Tuples : " + str(res))

Output

The original list is : [(None, 2), (None, None), (3, 4), (12, 3), (None,)] Removed None Tuples : [(None, 2), (3, 4), (12, 3)]

Time complexity: O(n), where n is the length of the input list.
Auxiliary space: O(n)

Method #3: Using count() method

If count of None in each tuple equals to length of tuple, then the entire tuple elements are None.Used this in if condition and appended other tuples to output list

Python3

# Python3 code to demonstrate working of # Remove None Tuples from List  # initializing list test_list = [(None, None), (None, None), (3, 4), (12, 3), (None, )]   # printing original list print("The original list is : " + str(test_list))  # negating result for discarding all None Tuples res=[] for i in test_list:     if not(i.count(None)== len(i)):         res.append(i)  # printing result print("Removed None Tuples : " + str(res))

Output

The original list is : [(None, None), (None, None), (3, 4), (12, 3), (None,)] Removed None Tuples : [(3, 4), (12, 3)]

Time Complexity: O(n)
Auxiliary Space: O(n)

Method #4: Using enumerate function

Python3

test_list = [(None, None), (None, None), (3, 4), (12, 3), (None, )]   res = [sub for i,sub in enumerate(test_list) if not all(ele == None for ele in sub)] print(res)

Output

[(3, 4), (12, 3)]

Time Complexity: O(n) where n is the number of elements in the list “test_list”. enumerate function performs n number of operations.
Auxiliary Space: O(n), extra space is required

Method #5 : Using operator.countOf()

Python3

# Python3 code to demonstrate working of # Remove None Tuples from List  # initializing list test_list = [(None, None), (None, None), (3, 4), (12, 3), (None, )]  # printing original list print("The original list is : " + str(test_list))  # negating result for discarding all None Tuples res=[] import operator for i in test_list:     if not(operator.countOf(i,None)== len(i)):         res.append(i)  # printing result print("Removed None Tuples : " + str(res))

Output

The original list is : [(None, None), (None, None), (3, 4), (12, 3), (None,)] Removed None Tuples : [(3, 4), (12, 3)]

Time Complexity : O(N)
Auxiliary Space : O(N)

Method 6: Using a for loop and slicing

In this method, we use a for loop to iterate through the list and remove the None tuples by slicing the list.

Python3

# Python3 code to demonstrate working of # Remove None Tuples from List  # initializing list test_list = [(None, None), (None, None), (3, 4), (12, 3), (None, )]   # printing original list print("The original list is : " + str(test_list))  # using for loop and slicing to remove None Tuples res = [] for i in range(len(test_list)):     if None not in test_list[i]:         res.append(test_list[i])  # printing result print("Removed None Tuples : " + str(res))

Output

The original list is : [(None, None), (None, None), (3, 4), (12, 3), (None,)] Removed None Tuples : [(3, 4), (12, 3)]

Time Complexity: O(n), where n is the length of the list
Auxiliary Space: O(n), where n is the length of the list (to store the result list)

Method 7: Using recursion

Step-by-step approach:

Define the original list
Define a recursive function that takes the original list and an empty list as arguments
The function should check if the original list is empty
If it is, return the empty list
Otherwise, check if the first element of the list is a tuple containing None values
If it is, call the function recursively with the remaining elements of the list and the empty list
Otherwise, append the first element of the list to the empty list and call the function recursively with the remaining elements of the list and the updated list
Call the recursive function with the original list and an empty list as arguments and assign the result to a new variabl

Python3

# Define the original list test_list = [(None, None), (None, None), (3, 4), (12, 3), (None, )]  # Define the recursive function def remove_none_tuples(lst, res):     if not lst:         return res     elif None in lst[0]:         return remove_none_tuples(lst[1:], res)     else:         res.append(lst[0])         return remove_none_tuples(lst[1:], res)  # Call the recursive function with the original list and an empty list new_list = remove_none_tuples(test_list, [])  # Print the new list print("Removed None Tuples : " + str(new_list))