Remove Empty Tuples from a List - Python

Given a list that contains both empty and non-empty tuples, the task is to remove all empty tuples from the list. For Example:

Input: [(1, 2), (), (3, 4), (), (5,)]
Output: [(1, 2), (3, 4), (5,)]

Let’s explore different methods to remove empty tuples from a list in Python.

Using List Comprehension

List comprehension provides a concise way to filter elements. It iterates through the list and includes only tuples that evaluate to True.

a = [(1, 2), (), (3, 4), (), (5,)]
res = [t for t in a if t]
print(res)

[(1, 2), (3, 4), (5,)]

Explanation :

• if 't' filters out tuples that are empty because empty tuples evaluate to False.
• A new list is returned containing only non-empty tuples.

Using filter()

The filter() function removes elements that are falsy when the first argument is None.

a = [(1, 2), (), (3, 4), (), (5,)]
res = list(filter(None, a))
print(res)

[(1, 2), (3, 4), (5,)]

Explanation:

• filter(None, a): keeps all elements that evaluate to True.
• Empty tuples are ignored since they are falsy in Python.
• Converting the result to a list gives the filtered output.

Using itertools.compress()

compress() allows filtering based on a boolean mask, which is constructed using the truth value of each tuple.

from itertools import compress

a = [(1, 2), (), (3, 4), (), (5,)]
res = list(compress(a, [bool(t) for t in a]))
print(res)

[(1, 2), (3, 4), (5,)]

Explanation:

• bool(t): returns True for non-empty tuples, False for empty tuples.
• compress(a, mask): selects elements from a where the mask is True.
• The result is a new list with empty tuples removed.

Using a For Loop

This basic approach removes empty tuples from a list using a for loop and append(). It checks each tuple and appends only non-empty tuples to a new list.

a = [(1, 2), (), (3, 4), (), (5,)]
res = [] 

for t in a:
    if t:
        res.append(t)
print(res)

[(1, 2), (3, 4), (5,)]

Explanation:

• Each tuple 't' is checked in a conditional if t.
• Non-empty tuples are appended to res.

Related Articles:

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