# 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]

"""

https://blog.csdn.net/weixin_43790276/article/details/104033622
"""
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2、计算x的n次⽅的⽅法
# 2、计算x的n次⽅的⽅法

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

x = 2
a = power(x,4)
print(a)
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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
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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
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5、列出当前⽬录下的所有⽂件和⽬录名
# 5、列出当前⽬录下的所有⽂件和⽬录名
import os

ml = [d for d in os.listdir('.')]
print(ml)
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6、把⼀个list中所有的字符串变成⼩写
# 6、把⼀个list中所有的字符串变成⼩写
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)
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7、输出某个路径下的所有⽂件和⽂件夹的路径
#7、输出某个路径下的所有⽂件和⽂件夹的路径
import os

def print_dir():
filepath = input("请输入一个路径：")
if filepath == "":
print("请输入正确的路径")
else:
for i in os.listdir(filepath):  #获取目录中的文件及子目录列表
print(os.path.join(filepath,i))  #把路径组合起来

print( print_dir() )
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8、打印输出某个路径及其⼦⽬录下的所有⽂件的绝对路径

#8、打印输出某个路径及其⼦⽬录下的所有⽂件的绝对路径

import os
def show_dir(filepath):
for i in os.listdir(filepath):
path = (os.path.join(filepath, i))
print(path)
if os.path.isdir(path):  #isdir()判断是否是目录
show_dir(path)       #如果是目录，使用递归方法

filepath = "C:\Program Files\Microsoft VS Code"
show_dir(filepath)
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9、输出某个路径及其⼦⽬录下所有以.html为后缀的⽂件
# 9、输出某个路径及其⼦⽬录下所有以.html为后缀的⽂件
import os
def print_dir(filepath):
for i in os.listdir(filepath):
path = os.path.join(filepath, i)
if os.path.isdir(path):
print_dir(path)
if path.endswith(".html"):
print(path)

filepath = "F:\PycharmProjects"
print_dir(filepath)
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10、把原字典的键值对颠倒并⽣产新的字典
#  10、把原字典的键值对颠倒并⽣产新的字典

dict1 = {"A":"a","B":"b","C":"c"}
dict2 = { v:k for k,v in dict1.items()}
print(dict2)
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posted @ 2022-02-11 10:42  Marlon康  阅读(67)  评论(0编辑  收藏  举报