Python冒泡排序，python冒泡,# -*- coding

Python冒泡排序，python冒泡,# -*- coding

# -*- coding: utf-8 -*-def bubble_sort(seq, cmp=cmp):    """冒泡排序，伪码如下：    BUBBLESORT(A)    1  for i ← 1 to length[A]    2    do for j ← length[A] downto i+1    3      do if A[j] < A[j-1]    4        then exchange A[j] &#8596; A[j-1]    T(n) = θ(n^2)    Args:        seq (Sequence): 一个序列对象。        cmp (Function): 比较函数。默认为内建函数cmp()。    Returns:        一个排序后的列表。    """    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-1]:                seq[j], seq[j-1] = seq[j-1], seq[j]    return seqif __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))#该片段来自于http://byrx.net