Python: Calculate the difference between two iterables, without filtering duplicate values

Last update on April 19 2025 13:00:58 (UTC/GMT +8 hours)

Difference Without Filtering Duplicates

Write a Python program to calculate the difference between two iterables, without filtering duplicate values.

Create a set from y.
Use a list comprehension on x to only keep values not contained in the previously created set, _y.

Sample Solution:

Python Code:

# Define a function 'difference' that takes two lists 'x' and 'y'.
# It converts 'y' into a set for faster membership checking.
# It returns a new list containing elements that are in 'x' but not in 'y'.
def difference(x, y):
    _y = set(y)
    return [item for item in x if item not in _y]

# Call the 'difference' function with two lists and print the result.
print(difference([1, 2, 3], [1, 2, 4]))

Sample Output:

[3]

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to compute the difference between two lists, preserving duplicate occurrences in the result.
Write a Python program to calculate the difference between two iterables including duplicates, then output both the difference and the count of duplicates.
Write a Python program to determine the difference between two lists without filtering duplicates and maintain the original order of appearance.
Write a Python program to find elements present in one list but not in another, considering duplicate values.

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