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正则与计算器

时间:2017-06-29 22:35:45      阅读:238      评论:0      收藏:0      [点我收藏+]

标签:while   replace   break   ret   重复   racket   choice   bsp   计算器   

import re

def repeat_func(s):
    #去掉重复的+——号
    repeat = re.findall(\+\-|\-\-|\++\-\+, s)
    if len(repeat) > 0:
        for i in repeat:
            if i == -- or i == ++:
                s = s.replace(i, +)
            if i == +- or s == -+:
                s = s.replace(i, -)
    return s

def mul_devid(content):
    # 计算乘除
    pattern1 = -?\d+\.?\d*(?:\*|\/)-?\d+\.?\d*
    while 1:
        first = re.search(pattern1, content)
        #匹配乘除
        if first:
            if * in first.group():
                new1 = first.group().split(*)
                new = float(new1[0]) * float(new1[1])
                new = str(new)
            else:
                new1 = first.group().split(/)
                new = float(new1[0]) / float(new1[1])
                new = str(new)

            res=re.search(r-\d+\.?\d*(?:\*|\/)-\d+\.?\d*,content)
            #如果两个负数相乘或相除,添加正号
            if res :
                new=+ + new
            content = repeat_func(content)
            content = content.replace(first.group(), new)

        else:
            break
    return content

def add_minus(content):
    # 计算加减
    pattern2 = -?\d+\.?\d*(?:\+|\-)\d+\.?\d*
    while 1:
        first = re.search(pattern2, content)
        if first:
            #根据不同的模式分别计算
            choice1 = re.search((-\d+\.?\d*-\d+\.?\d*), first.group())
            if choice1:
                new1 = first.group().split(-)
                new = -(float(new1[1]) + float(new1[2]))

            choice2 = re.search((-\d+\.?\d*\+\d+\.?\d*)|(\d+\.?\d*\+\d+\.?\d*), first.group())
            if choice2:
                new1 = first.group().split(+)
                new = float(new1[1]) + float(new1[0])

            choice3 =  re.search(\d+\.?\d*-\d+\.?\d*, first.group())
            if choice3:
                new1 = first.group().split(-)
                new = float(new1[0]) - float(new1[1])
            #
            # content=repeat_func(content)
            content = content.replace(first.group(), str(new))

        else:
            break

    return content

def calculate(content):
    content = mul_devid(content)
    content = add_minus(content)
    return content

def bracket(s):
    while 1:
        first = re.search(r\([^()]+\), s)
        if first:
            new=calculate(first.group())
            s=s.replace(first.group(),new[1:-1])
            s=repeat_func(s)
        else: break
    end=calculate(s)
    return end

s=1-2*((60-30+(-40/5)*(9-2*5/3+7/3*99/4*2998+10*568/14))-(-4*3)/(16-3*2))

print(eval(s))
print(bracket(s))

 

正则与计算器

标签:while   replace   break   ret   重复   racket   choice   bsp   计算器   

原文地址:http://www.cnblogs.com/mona524/p/7096193.html

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