Python/sorts/bucket_sort.py

#!/usr/bin/env python
# Author: OMKAR PATHAK
# This program will illustrate how to implement bucket sort algorithm

# Wikipedia says: Bucket sort, or bin sort, is a sorting algorithm that works by distributing the
# elements of an array into a number of buckets. Each bucket is then sorted individually, either using
# a different sorting algorithm, or by recursively applying the bucket sorting algorithm. It is a
# distribution sort, and is a cousin of radix sort in the most to least significant digit flavour.
# Bucket sort is a generalization of pigeonhole sort. Bucket sort can be implemented with comparisons
# and therefore can also be considered a comparison sort algorithm. The computational complexity estimates
# involve the number of buckets.

#  Time Complexity of Solution:
#  Best Case O(n); Average Case O(n); Worst Case O(n)

DEFAULT_BUCKET_SIZE=5

def bucket_sort(my_list, bucket_size=DEFAULT_BUCKET_SIZE):
    if len(my_list) == 0:
        raise Exception("Please add some elements in the array.")

    min_value, max_value = (min(my_list), max(my_list))
    bucket_count = ((max_value - min_value) // bucket_size + 1)
    buckets = [[] for _ in range(int(bucket_count))]

    for i in range(len(my_list)):
        buckets[int((my_list[i] - min_value) // bucket_size)].append(my_list[i])

    return sorted([buckets[i][j] for i in range(len(buckets))
                                 for j in range(len(buckets[i]))])

if __name__ == "__main__":
    user_input = input('Enter numbers separated by a comma:').strip()
    unsorted = [float(n) for n in user_input.split(',') if len(user_input) > 0]
    print(bucket_sort(unsorted))