python计算器

代码中肯定还有一些思维漏洞，望参考者留言交流。

界面：

 演示视频：https://files.cnblogs.com/files/acm-jing/calculator.rar

代码:

# coding=utf-8
from tkinter import *
import math
import re


#the main gui
window=Tk()
window.title('Calculator')
window.geometry('450x260')
mainFrame=Frame(bg='black')

#-----------button click event
def ButtonClick(buttonText): #except '=',use to show the expression on the entry
    global showRes,res,oneInput
    if buttonText!='clear' and buttonText!='back':
        oneInput.append(buttonText)
        showRes=showRes+buttonText
    elif buttonText=='clear':
        showRes=''
        oneInput.clear()
    else:
        if showRes!='':
            showRes=showRes[0:len(showRes)-len(oneInput.pop())]
    res.set(showRes)

def MultDiv(expression,op):#multiply and divid operations
    loc=expression.index(op)
    if op=='×' and expression[loc+1]!='-':
        tempRes=float(expression[loc-1])*float(expression[loc+1])
    elif op=='÷' and expression[loc+1]!='-':#calculate divid,not:divisor is 0
        tempRes = float(expression[loc-1])/float(expression[loc+1])
    elif op=='×' and expression[loc+1]=='-':
        tempRes = -float(expression[loc - 1]) * float(expression[loc + 2])
        del expression[loc-1]
    elif op == '÷' and expression[loc + 1] == '-':
        tempRes = -float(expression[loc - 1]) / float(expression[loc + 2])
        del expression[loc - 1]
    del expression[loc-1],expression[loc-1],expression[loc-1]
    expression.insert(loc-1,str(tempRes))
    return expression

def SingelValueFunction(expression,loc):
    op=expression[loc]
    if op=='sin ':
        if expression[loc+1]!='-':
            temRes=math.sin(float(expression[loc+1]))
        else:
            temRes=math.sin(-float(expression[loc+2]))
            del expression[loc]
    elif op=='cos ':
        if expression[loc+1]!='-':
            temRes=math.cos(float(expression[loc+1]))
        else:
            temRes=math.cos(-float(expression[loc+2]))
            del expression[loc]
    elif op=='tan ':
        if expression[loc+1]!='-':
            temRes=math.tan(float(expression[loc+1]))
        else:
            temRes=math.tan(-float(expression[loc+2]))
            del expression[loc]
    elif op=='abs ':
        if expression[loc+1]!='-':
            temRes=float(expression[loc+1])
        else:
            temRes=float(expression[loc+2])
            del expression[loc]
    elif op=='ln ':
        if expression[loc+1]!='-':
            temRes=math.log(2.718281828,float(expression[loc+1]))
        else:
            temRes = math.log(2.718281828, -float(expression[loc + 2]))
            del expression[loc]
    elif op=='sqrt ':
        if expression[loc+1]!='-':
            temRes=math.sqrt(float(expression[loc+1]))
        else:
            temRes=math.sqrt(-float(expression[loc+2]))
            del expression[loc]
   # elif
    del expression[loc],expression[loc]
    expression.insert(loc,str(temRes))
    return expression

def Pi(expression,op):
    loc = expression.index(op)
    temRes = 3.1415926535
    del expression[loc]
    expression.insert(loc,temRes)
    return expression

def E(expression,op):
    loc=expression.index(op)
    temRes=2.718281828
    del expression[loc]
    expression.insert(loc,str(temRes))
    return expression

def Factorial(expression,op):
    loc=expression.index(op)
    temRes=math.factorial(float(expression[loc-1]))
    del expression[loc-1],expression[loc-1]
    expression.insert(loc-1,str(temRes))
    return expression

def Power(expression,op):
    loc=expression.index(op)
    if expression[loc+1]!='-':
        temRes=math.pow(float(expression[loc-1]),float(expression[loc+1]))
    else:
        temRes = math.pow(float(expression[loc - 1]), -float(expression[loc + 2]))
        del expression[loc-1]
    del expression[loc-1],expression[loc-1],expression[loc-1]
    expression.insert(loc-1,str(temRes))
    return expression

def WithoutBracketsExpressionCalculate(strExpression):
    expression = re.findall('([d.]+|÷|-|+|×+|sin |cos |tan |ln |abs |sqrt |π|e|!|^)', strExpression)
    print(expression)
    if expression[0] == '-':  # negative number
        expression[0] = expression[0] + expression[1]
        del expression[1]
    sum=0
    #use value to replace the e and π
    while 'e' in expression:
        E(expression,'e')
    while 'π' in expression:
        Pi(expression,'π')
    # calculate single value function
    while '!' in expression:
        Factorial(expression,'!')

    singleValueFunctonIndexs=[]
    for i in range(len(expression)):
        if expression[i] in ['sin ','cos ','tan ','ln ','abs ','sqrt ']:
            singleValueFunctonIndexs.append(i)
    singleValueFunctonNums=len(singleValueFunctonIndexs)
    for j in range(singleValueFunctonNums):
        SingelValueFunction(expression,singleValueFunctonIndexs[singleValueFunctonNums-1-j])

    while '^' in expression:
        Power(expression,'^')

    while True:
        #calculate mul and div first
        if '×' in expression and '÷'not in expression:
            MultDiv(expression,'×')
        elif '×'not in expression and '÷'in expression:
            MultDiv(expression,'÷')
        elif '÷'in expression and '×'in expression:
            locMul=expression.index('×')
            locDiv=expression.index('÷')
            if locMul<locDiv:
                MultDiv(expression,'×')
            else:
                MultDiv(expression,'÷')
        #calculate add and minus
        else:

            sum+=float(expression[0])

            for i in range(1,len(expression),2):#step 2
                if expression[i]=='+' and expression[i+1]!='-':
                    sum+=float(expression[i+1])
                elif expression[i]=='+' and expression[i+1]=='-':
                    sum-=float(expression[i+2])
                elif expression[i]=='-' and expression[i+1]!='-':
                    sum-=float(expression[i+1])
                elif expression[i]=='-' and expression[i+1]=='-':
                    sum+=float(expression[i+2])
            break
    # if(len(expression)==1):
    #     return sum
    # else:
    #     return 'Syntax ERROR'
    return sum

def WithBracketsExpressionCalculate(expression):
    leftBrackes=[] #record the location of '('
    ans=0

    if '(' not in expression:
        ans=WithoutBracketsExpressionCalculate(expression)
        return ans

    for i in range(len(expression)):
        if expression[i]=='(':
            leftBrackes.append(i)
        elif expression[i]==')':
            subExpression=expression[leftBrackes[len(leftBrackes)-1]+1:i]
            tempAns=WithoutBracketsExpressionCalculate(subExpression)
            expression=expression[0:leftBrackes[len(leftBrackes)-1]]+str(tempAns)+expression[i+1:len(expression)+1]
            leftBrackes.pop()
            return WithBracketsExpressionCalculate(expression)


def ButtonEqual():
    global showRes,res,oneInput
   # expression=re.findall('([d.]+|÷|-|+|×)',showRes)
    #print(expression)
    try:
        showRes=str(WithBracketsExpressionCalculate(showRes))
    except Exception:
        showRes='Syntax ERROR'
    #---------use eval() to calculate the expression
    #strExpression = ''
    # for i in range(len(expression)):
    #     strExpression+=expression[i]
    #showRes=eval(strExpression)
    #---------use eval() to calculate the expression
    #print(oneInput)
    oneInput.clear()
    oneInput.append(showRes)
    res.set(showRes)

#------glaobal variabls
global showRes
global oneInput
global res
showRes=''
oneInput=[]
res=StringVar()
res.set(showRes)


#--------output
entryShow=Entry(mainFrame,bg='#121212',foreground='white',font=('TimesNewRoman', '15', 'normal'),borderwidth=6,width=300,textvariable=res)
entryShow.pack(padx=5,pady=5)

#--------function

#sin function
buttonSin=Button(mainFrame,command=lambda :ButtonClick(buttonText='sin '),width=3,height=1,bg='#212121',text='sin',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonSin.place(x=5,y=55)
#ln function
buttonLn=Button(mainFrame,command=lambda :ButtonClick(buttonText='ln '),width=3,height=1,bg='#212121',text='ln',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonLn.place(x=60,y=55)
#cos
buttonCos=Button(mainFrame,command=lambda :ButtonClick(buttonText='cos '),width=3,height=1,bg='#212121',text='cos',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonCos.place(x=5,y=87)
#abs
buttonAbs=Button(mainFrame,command=lambda :ButtonClick(buttonText='abs '),width=3,height=1,bg='#212121',text='abs',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonAbs.place(x=60,y=87)
#tan
buttonLog=Button(mainFrame,command=lambda :ButtonClick(buttonText='tan '),width=3,height=1,bg='#212121',text='tan',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonLog.place(x=5,y=119)
#e
buttonE=Button(mainFrame,command=lambda :ButtonClick(buttonText='e'),width=3,height=1,bg='#212121',text='e',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonE.place(x=60,y=119)
#pi
buttonPI=Button(mainFrame,command=lambda :ButtonClick(buttonText='π'),width=3,height=1,bg='#212121',text='π',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonPI.place(x=5,y=151)
#^
buttonIndex=Button(mainFrame,command=lambda :ButtonClick(buttonText='^'),width=3,height=1,bg='#212121',text='^',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonIndex.place(x=60,y=151)
#!
buttonFactorial=Button(mainFrame,command=lambda :ButtonClick(buttonText='!'),width=3,height=1,bg='#212121',text='!',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonFactorial.place(x=5,y=183)
#sqrt
buttonSqrt=Button(mainFrame,command=lambda :ButtonClick(buttonText='sqrt '),width=3,height=1,bg='#212121',text='√',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonSqrt.place(x=60,y=183)
#clear
buttonClear=Button(mainFrame,command=lambda :ButtonClick(buttonText='clear'),width=3,height=1,bg='#212121',text='clear',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonClear.place(x=5,y=215)
#back
buttonBack=Button(mainFrame,command=lambda :ButtonClick(buttonText='back'),width=3,height=1,bg='#212121',text='back',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonBack.place(x=60,y=215)
#---------number

#7
button7=Button(mainFrame,command=lambda :ButtonClick(buttonText='7'),width=3,height=2,bg='#424242',text='7',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button7.place(x=140,y=55)
#8
button8=Button(mainFrame,command=lambda :ButtonClick(buttonText='8'),width=3,height=2,bg='#424242',text='8',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button8.place(x=195,y=55)
#9
button9=Button(mainFrame,command=lambda :ButtonClick(buttonText='9'),width=3,height=2,bg='#424242',text='9',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button9.place(x=250,y=55)
#4
button4=Button(mainFrame,command=lambda :ButtonClick(buttonText='4'),width=3,height=2,bg='#424242',text='4',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button4.place(x=140,y=103)
#5
button5=Button(mainFrame,command=lambda :ButtonClick(buttonText='5'),width=3,height=2,bg='#424242',text='5',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button5.place(x=195,y=103)
#6
button6=Button(mainFrame,command=lambda :ButtonClick(buttonText='6'),width=3,height=2,bg='#424242',text='6',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button6.place(x=250,y=103)
#1
button1=Button(mainFrame,command=lambda :ButtonClick(buttonText='1'),width=3,height=2,bg='#424242',text='1',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button1.place(x=140,y=151)
#2
button2=Button(mainFrame,command=lambda :ButtonClick(buttonText='2'),width=3,height=2,bg='#424242',text='2',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button2.place(x=195,y=151)
#3
button3=Button(mainFrame,command=lambda :ButtonClick(buttonText='3'),width=3,height=2,bg='#424242',text='3',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button3.place(x=250,y=151)
#0
button0=Button(mainFrame,command=lambda :ButtonClick(buttonText='0'),width=10,height=2,bg='#424242',text='0',font=('TimesNewRoman', '12', 'normal'),foreground='white')
button0.place(x=140,y=199)
#.
buttonDot=Button(mainFrame,command=lambda :ButtonClick(buttonText='.'),width=3,height=2,bg='#424242',text='.',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonDot.place(x=250,y=199)

#------------operations
#divide
buttonDiv=Button(mainFrame,command=lambda :ButtonClick(buttonText='÷'),width=3,height=2,bg='#212121',text='÷',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonDiv.place(x=335,y=55)
#left bracket
buttonLBracket=Button(mainFrame,command=lambda :ButtonClick(buttonText='('),width=3,height=2,bg='#212121',text='(',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonLBracket.place(x=390,y=55)
#multiply
buttonMul=Button(mainFrame,command=lambda :ButtonClick(buttonText='×'),width=3,height=2,bg='#212121',text='×',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonMul.place(x=335,y=103)
#right bracket
buttonRBracket=Button(mainFrame,command=lambda :ButtonClick(buttonText=')'),width=3,height=2,bg='#212121',text=')',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonRBracket.place(x=390,y=103)
#minus
buttonMinus=Button(mainFrame,command=lambda :ButtonClick(buttonText='-'),width=3,height=2,bg='#212121',text='-',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonMinus.place(x=335,y=151)
#add
buttonMinus=Button(mainFrame,command=lambda :ButtonClick(buttonText='+'),width=3,height=2,bg='#212121',text='+',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonMinus.place(x=335,y=199)
#equal
buttonMinus=Button(mainFrame,command=ButtonEqual,width=3,height=5,bg='#212121',text='=',font=('TimesNewRoman', '12', 'normal'),foreground='white')
buttonMinus.place(x=390,y=151)

mainFrame.pack(expand='yes',fill='both')
window.mainloop()

 测试样例：