Python implements bubble sorting

python algorithm - python implements bubble sort

Operation principle of bubble sort:

Compare adjacent elements. If the first one is bigger than the second one, swap them both.

Do the same for each pair of adjacent elements, starting with the first pair and ending with the last pair. At this point, the last element should be the largest number.

Repeat the above steps for all elements except the last one.

Continue repeating the above steps for fewer and fewer elements each time until there are no pairs of numbers to compare.

Example code

# -*- encoding: utf-8 -*-

def bubble_sort(seq, cmp=cmp):

"""Bubble sort, the pseudo code is as follows:

BUBBLESORT(A)

1 for i ← 1 to length[A]

2 do for j ← length[A] downto i+1

3 do if A[j]

4                                                                                                                                                                                                                                                 .

cmp (Function): The default is the built-in function cmp(). Returns:

"""

if (seq == None):

return None

length = len(seq)

for i in range(length):

for j in range(length-1, i, -1):

if seq[j]                                                                                                                                                                                               seq[j], seq[j-1] = seq[j-1], seq[j]

return seq

if __name__ == '__main__':

Import random, timeit

items = range(10000)

random.shuffle(items)

def test_sorted():

print(items)

sorted_items = sorted(items)

print(sorted_items)

def test_bubble_sort():

print(items)

sorted_items = bubble_sort(items)

print(sorted_items)

test_methods = [test_sorted, test_bubble_sort]

for test in test_methods:

       name = test.__name__ # test.func_name

       t = timeit.Timer(name + '()', 'from __main__ import ' + name)

       print(name + ' takes time : %f' % t.timeit(1))