Python with parentheses in the calculator

The calculator with parentheses is also the first self-feeling to finish the best after all really got one weeks although the early stage of the road is really hard to go I will try to refuel Python learn practical

Refer to two bloggers ' articles

Http://www.cnblogs.com/0zcl/p/5983236.html

http://www.cnblogs.com/loyfee/p/5764926.html#3538071

The general process is to first convert the input data into a list to remove null characters

Then find the innermost parentheses and then put the results back in the list and figure out the results.

Import Re#data= Input ("Please enter arithmetic:") def change_list (data): Data=re.sub (" ","", data) #将空格转为""# Print (data) data_list= []     forIinchdata:data_list.append (i) Num=0    Try:         while 1:            ifdata_list[0] =="-": data_list[0] = data_list[0] + data_list[1] Data_list.pop (1)            ifdata_list[num].isnumeric ():ifdata_list[num+1].isnumeric (): Data_list[num]= data_list[num]+data_list[num+1] Data_list.pop (num+1)                Else: Num+=1            Else: Num+=1except Indexerror ase: #print (E,"index out of bounds")        returnData_list #ifData_list.index (data_list[-1]) <Num: # print (data_list) # Breakdef COMPUTE (data): while 1: #判断乘除if "*" inchData or"/" inchData: forI,jinchEnumerate (data):ifj = ="*": Data[i+1] =int(data[i-1]) *int(data[i+1]) Data.pop (i-1) Data.pop (i-1)                     Break                ifj = ="/": Data[i+1] =int(data[i-1]) *int(data[i+1]) Data.pop (i-1) Data.pop (i-1)                     Break#判断加减if "+" inchData or"-" inchData: forI,jinchEnumerate (data):ifj = ="+": Data[i+1] =int(Data[i-1]) +int(Data[i +1]) Data.pop (i-1) Data.pop (i-1)                     Break                ifj = ="-": Data[i+1] =int(Data[i-1]) -int(Data[i +1]) Data.pop (i-1) Data.pop (i-1)                     Break        Else:            returnData Break#有括号和无括号运算"""If there are parentheses, the innermost "") will be used to find its first "(" using: Intercept the middle number of the operation, then return the list until there is no parentheses to jump out of the operation"""def parenth (data):if "(" inchData: while 1:            if ")" inchdata:b= Data.index (")") #表示第一个 ")" #print (b) forIinchRange (b,-1,-1): #截取最里层括号进行运算 #print (i)ifData[i] = ="(": New_list=[] new_list=data[i+1: b]byte=compute (new_list) [0] del (data[i:b+1]) Data.insert (i,byte)                         Break            Else:                returnCompute (data)Else: Compute (data) while 1: Data= Input ("Please enter the calculation:")    ifdata = ="":ContinueData=change_list (data) parenth (data) print (data[0])    ifInput"if input q exits: \ n") =="Q": Exit ()

Python with parentheses in the calculator