#计算器开发需求

#

#1、实现加减乘除及拓号优先级解析

#2、用户输入 1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )等类似公式后，

#必须自己解析里面的(),+,-,*,/符号和公式，运算后得出结果，结果必须与真实的计算器所得出的结果一致

import re

import functools

def minus_operator_handler(formula):

'''处理一些特殊的符号'''

minus_operator = re.split("-",formula)

calc_list = re.findall("[0-9]",formula)

if minus_operator[0] == '':#第一值肯定是负号

clac_list[0] = '-%s' % calc_list[0]

res = functools.reduce(lambda x,y:float(x) - float(y),calc_list)

print("\33[33;1m减号[%s]处理结果：\033[0m" % formula,res)

return res

def remove_duplicates(formula):

formula = formula.replace("++","+")

formula = formula.replace("+-","-")

formula = formula.replace("-+","-")

formula = formula.replace("--","+")

formula = formula.replace("- -","+")

return formula

def compute_mutiply_dividend(formula):

'''算乘除，传进来的是字符串'''

operators = re.findall("[*/]",formula)

calc_list = re.split("[*/]",formula)

res = None

for index,i in enumerate(calc_list):

if res:

if operators[index-1] == "*":

res *= float(i)

else operators[index-1] == "/"

res /= float(i)

else:

res = float(i)

print("\033[31;1m[%s]运算结果=\033[0m" %formula, res)

return res

def handle_minus_in_list(operators_list,calc_list):

for index,i in enumerate(calc_list):

if i == '':#它其实代表负号，改成负号

calc_list[index+1] = i + calc_list[index+1].strip()

def handle_special_occactions(plus_and_minus_operators,multiply_and_dividend):

for index,i in enumerate(multiply_and_dividend):

i = i.strip()

if i.endswith("*") or i.endswith("/"):

multiply_and_dividend[index] = multiply_and_dividend[index] + plus_and_minus_operators[index] + multiply_and_dividend[index+1]

del multiply_and_dividend[index+1]

del plus_and_minus_operators[index]

return plus_and_minus_operators,multiply_and_dividend

def compute(formula):

'''这里计算的是不带括号的公式'''

formula = formula.strip("()")#去除外面包的括号

formula = remove_duplicates(formula)#去除外重复的+-号

plus_and_minus_operators = re.findall("[+-]",formula)

multiply_and_dividend = re.split("[+-]",formula)#取出乘除公式

if len(multiply_and_dividend[0].strip()) == 0:#代表这肯定是个减号

multiply_and_dividend[1] = plus_and_minus_operators[0] + multiply_and_dividend[1]

del multiply_and_dividend[0]

del plus_and_minus_operators[0]

plus_and_minus_operators,multiply_and_dividend=handle_special_occactions(plus_and_minus_operators,multiply_and_dividend)

for index,i in enumerate(multiply_and_dividend):

if re.search("[*/]",i):

sub_res = compute_mutiply_dividend(i)

multiply_and_dividend[index] = sub_res

#开始运算+，-

print(multiply_and_dividend,plus_and_minus_operators)

total_res = None

for index,item in enumerate(multiply_and_dividend):

if total_res:#代表不是第一次循环

if plus_and_minus_operators[index-1] == '+':

total_res += float(item)

elif plus_and_minus_operators[index-1] == '-':

total_res -= float(item)

else:

total_res = float(item)

print("\033[32;1m[%s]运算结果：\033[0m" %format,total_res)

return total_res

def calc(formula):

'''计算程序入口，主要逻辑是先计算括号里的值，算出来后再计算乘除，再算加减'''

parenthesise_flag = Ture

calc_res = None#初始化运算结果为None

while parenthesise_flag:

m = re.search("\[^()*\]",formula)#找到最里层的括号

if m:

#print("先算括号里的值：",m.group())

sub_res = compute(m.group())

formula = formula.replace(m.group(),str(sub_res))

else:

print('\033[41;1m----没括号了...---\033[0m')

print('\n\n033[42;1m最终结果:\033[0m',compute(formula))

parenthesise_flag = False#代表公式里的括号已经都被剥除

if __name__ == '__main__':