Python – Filter tuple with all same elements

When it is required to filter out tuples that contain only identical elements, a list comprehension combined with the set function and len method can be used. This approach leverages the fact that a set of identical elements has length 1.

How It Works

The filtering logic works by converting each tuple to a set. Since sets contain only unique elements, a tuple with all identical elements will produce a set of length 1.

Example

Below is a demonstration of filtering tuples with all same elements ?

my_list = [(31, 54, 45, 11, 99), (11, 11), (45, 45, 45), (31, 54, 45, 11, 99), (99, 99), (0, 0)]

print("The list is:")
print(my_list)

my_result = [sub_list for sub_list in my_list if len(set(sub_list)) == 1]

print("The resultant list is:")
print(my_result)

Output

The list is:
[(31, 54, 45, 11, 99), (11, 11), (45, 45, 45), (31, 54, 45, 11, 99), (99, 99), (0, 0)]
The resultant list is:
[(11, 11), (45, 45, 45), (99, 99), (0, 0)]

Alternative Methods

Using all() Function

You can also use the all() function to check if all elements are equal to the first element ?

my_list = [(31, 54, 45, 11, 99), (11, 11), (45, 45, 45), (99, 99), (0, 0)]

my_result = [tup for tup in my_list if len(tup) > 0 and all(x == tup[0] for x in tup)]

print("Filtered tuples:")
print(my_result)

Filtered tuples:
[(11, 11), (45, 45, 45), (99, 99), (0, 0)]

Explanation

• A list of tuples is defined and displayed on the console.

• List comprehension iterates over each tuple in the list.

• The condition len(set(sub_list)) == 1 checks if all elements are identical by converting the tuple to a set.

• If the set has only one unique element, the tuple passes the filter.

• The filtered tuples are stored in a new list and displayed as output.

Conclusion

Using len(set(tuple)) == 1 is the most efficient way to filter tuples with identical elements. The all() function provides a readable alternative for the same task.