Python: Count the frequency of consecutive duplicate elements in a given list of numbers, use itertools module

Last update on April 22 2025 12:51:15 (UTC/GMT +8 hours)

31. Count Consecutive Duplicates

Write a Python program to count the frequency of consecutive duplicate elements in a given list of numbers. Use the itertools module.

Sample Solution:

Python Code:

from itertools import groupby
def count_same_pair(nums):
    result = [sum(1 for _ in group) for _, group in groupby(nums)]
    return result

nums = [1,1,2,2,2,4,4,4,5,5,5,5]
print("Original lists:")
print(nums)
print("\nFrequency of the consecutive duplicate elements:")
print(count_same_pair(nums))

Sample Output:

Original lists:
[1, 1, 2, 2, 2, 4, 4, 4, 5, 5, 5, 5]

Frequency of the consecutive duplicate elements:
[2, 3, 3, 4]

For more Practice: Solve these Related Problems:

Write a Python program to count the frequency of consecutive duplicate elements in a list using itertools.groupby and return a list of (element, count) tuples.
Write a Python program to create an iterator that yields the count of consecutive duplicates and then computes the maximum frequency.
Write a Python program to iterate over a list and compress consecutive duplicate numbers into a tuple of (number, repetition) using groupby.
Write a Python program to count consecutive duplicates in an unordered list by first sorting it, then grouping using itertools.groupby.

Go to:

Previous: Write a Python program to create non-repeated combinations of Cartesian product of four given list of numbers.
Next: Write a Python program to count the frequency of the elements of a given unordered list.

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.