Python Program for Bubble Sort

Bubble Sort is the simplest sorting algorithm that works by repeatedly swapping the adjacent elements if they are in the wrong order. 

Python3

# Python program for implementation of Bubble Sort

def bubbleSort(arr):
    n = len(arr)
    # optimize code, so if the array is already sorted, it doesn't need
    # to go through the entire process
    swapped = False
    # Traverse through all array elements
    for i in range(n-1):
        # range(n) also work but outer loop will
        # repeat one time more than needed.
        # Last i elements are already in place
        for j in range(0, n-i-1):

            # traverse the array from 0 to n-i-1
            # Swap if the element found is greater
            # than the next element
            if arr[j] > arr[j + 1]:
                swapped = True
                arr[j], arr[j + 1] = arr[j + 1], arr[j]

        if not swapped:
            # if we haven't needed to make a single swap, we
            # can just exit the main loop.
            return


# Driver code to test above
arr = [64, 34, 25, 12, 22, 11, 90]

bubbleSort(arr)

print("Sorted array is:")
for i in range(len(arr)):
    print("% d" % arr[i], end=" ")

Output

Sorted array is:
 11  12  22  25  34  64  90 

Time Complexity:  O(n²).

Auxiliary Space: O(1).

Please refer complete article on Bubble Sort for more details! 

Python3

def bubblesort(elements):
    swapped = False
    # Looping from size of array from last index[-1] to index [0]
    for n in range(len(elements)-1, 0, -1):
        for i in range(n):
            if elements[i] > elements[i + 1]:
                swapped = True
                # swapping data if the element is less than next element in the array
                elements[i], elements[i + 1] = elements[i + 1], elements[i]
        if not swapped:
            # exiting the function if we didn't make a single swap
            # meaning that the array is already sorted.
            return

elements = [39, 12, 18, 85, 72, 10, 2, 18]

print("Unsorted list is,")
print(elements)
bubblesort(elements)
print("Sorted Array is, ")
print(elements)

Output

Unsorted list is,
[39, 12, 18, 85, 72, 10, 2, 18]
Sorted Array is, 
[2, 10, 12, 18, 18, 39, 72, 85]

Time Complexity:  O(n²). However in practice, this optimized version might take less time as when array gets sorted, function would return.

Auxiliary Space: O(1).