python 23day--python模块的应用
一、random模块的应用：
生成五为数字与字母组合的验证码：
1 import random 2 def v_code():#生成随机验证码 3 ret = '' 4 for i in range(5): 5 num = random.randint(0,9) 6 num1 = str(num) 7 ref = chr(random.randint(65,122)) 8 ret += random.choice([num1,ref]) 9 print(ret) 10 v_code()
二、re模块的应用
10个重要的re 的元字符：
^ 以什么开头
$ 以什么结尾
. 匹配任意字符（\除外）
* 匹配0到任意次
? 匹配0次或者1次（非贪婪模式）
+ 匹配1到任意次
{} {m，n}至少重复m次，最多重复n次
[] [a-z]匹配a到z的字符
() 分组
\ 转义
I 或的关系
计算器：
1 # 编辑者：闫龙 2 import re #导入re模块(正则表达式) 3 calc2 = "1-2*((60-30+(-40/52)*(9-2*5/3+7/3*-99/4*2998+10*568/14))-(-4*3)/(16-3*2))" 4 calc1 = "1-2*((60-30+(-40/5)*(9-2*5/3+7/3*99/4*2998+10*568/14))-(-4*3)/(16-3*2))" 5 calc = "1-2*((60*30+(-40/5)*(9*2*5/3+7/3*99/4*2998+10*568/14))-(-4*32)/(16-3*2))" 6 def Format(Str): 7 "格式化运算式" 8 Str = Str.replace("+-","-") 9 Str = Str.replace("-+", "-") 10 Str = Str.replace("++", "+") 11 Str = Str.replace("--", "+") 12 return Str 13 def SumCut(Str): 14 while re.search("-?[0-9]+\.?[0-9]*[-+][0-9]+\.?[0-9]*",Str): 15 newRes= re.search("-?[0-9]+\.?[0-9]*[-+][0-9]+\.?[0-9]*",Str) 16 WhatIs = newRes.group() 17 if(WhatIs.find("-") > 0): 18 l = WhatIs.split("-") 19 Str = Str.replace(WhatIs,str(float(l[0])-float(l[1]))) 20 elif(WhatIs.find("+") > 0): 21 l = WhatIs.split("+") 22 Str = Str.replace(WhatIs,str(float(l[0])+float(l[1]))) 23 return Str.replace("(","").replace(")","") 24 def MulDiv(Str): 25 while re.search("-?[0-9]+\.?[0-9]*[/*].?[0-9]+\.?[0-9]*",Str): 26 newRes= re.search("-?[0-9]+\.?[0-9]*[/*].?[0-9]+\.?[0-9]*",Str) 27 WhatIs = newRes.group() 28 if(WhatIs.find("/") > 0): 29 l = WhatIs.split("/") 30 Str = Str.replace(WhatIs,str(float(l[0])/float(l[1]))) 31 elif(WhatIs.find("*") > 0): 32 l = WhatIs.split("*") 33 if(float(l[0])<0 and float(l[1])<0): 34 Str = Str.replace(WhatIs, "+"+str(float(l[0]) * float(l[1]))) 35 else: 36 Str = Str.replace(WhatIs,str(float(l[0])*float(l[1]))) 37 return Format(Str) 38 while re.search("\([^()]+\)",calc): 39 res = re.search("\([^()]+\)", calc) 40 resTwo = MulDiv(Format(res.group())) 41 resTwo = SumCut(resTwo) 42 calc = calc.replace(res.group(),resTwo) 43 else: 44 resTwo = MulDiv(calc) 45 resTwo = SumCut(resTwo) 46 calc = resTwo 47 print(calc)
