Python练习-天已经亮了计算器也终于完成了

Posted 2020-09-15

 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)

以上,我什么也不想说,睡觉!