自学30个常用python实现

  1、 Python实现冒泡排序

# coding=utf-8
# Python实现冒泡排序
def bubble_sort(array):
    for i in range( len(array)-1):
        for j in range( len(array)-1-i):
            if array[j] > array[j+1]:
                array[j], array[j+1] = array[j+1], array[j]
    return array
 
 
if __name__ == '__main__':
    array = [10, 17, 50, 7, 30, 24, 27, 45, 15, 5, 36, 21]
    print(bubble_sort(array))
    #[5, 7, 10, 15, 17, 21, 24, 27, 30, 36, 45, 50]

"""
参考资料：
https://blog.csdn.net/weixin_43790276/article/details/104033622
"""

 2、计算x的n次?的?法

# 2、计算x的n次?的?法


def power(x, n ):
    s = 1
    while n > 0:
        n -= 1
        s = s * x
    return s


x = 2
a = power(x,4)
print(a)

3、计算a*a + b*b + c*c + ……

# 3、计算a*a + b*b + c*c + ……

def calc(*numbers):
    sum = 0
    for n in numbers:
        sum = sum + n*n
    return sum


if __name__ == '__main__':
    array = calc(1,2,3,4)
    print( array)
# 30

 4、计算阶乘 n!(用递归实现)

# 4、计算阶乘 n!(用递归实现)


def fact(num):
    if num < 0:
        return print("抱歉负数没有阶乘！")
    if num ==0:
        print("0 的阶乘为 1")
        return 1
    elif num==1:
        # print("1 的阶乘为 1")
        return 1
    elif num > 1:
        return num*fact(num-1)


"""
def factorial(n):
 return n*factorial(n-1) if n>1 else 1
print(factorial(5))
"""


if __name__ == '__main__':
    a=fact(6)
    print(a)  #720

5、列出当前?录下的所有?件和?录名

# 5、列出当前?录下的所有?件和?录名
import os

ml = [d for d in os.listdir('.')]
print(ml)

6、把?个list中所有的字符串变成?写

# 6、把?个list中所有的字符串变成?写
L = ["Hello", "World", "IBM", "Apple"]

def trans_lower(array):
    a = []
    for i in range( len(array) ):
        a.append( array[i].lower() )
    return a

if __name__ == '__main__':
    a = trans_lower(L)
    print(a)
    b = [s.lower() for s in L]
    print(b)