python怎么编写计算器程序

import tkinter #导入tkinter模块

root  = tkinter.Tk()

root.minsize(280,500)

root.title('李蛟龙的计算器')

#1.界面布局

#显示面板

result = tkinter.StringVar()

result.set(0)                      #显示面板显示结果1，用于显示默认数字0

result2 = tkinter.StringVar()           #显示面板显示结果2，用于显示计算过程

result2.set('')

#显示版

label = tkinter.Label(root,font = ('微软雅黑',20),bg = '#EEE9E9',bd ='9',fg = '#828282',anchor = 'se',textvariable

= result2)

label.place(width = 280,height = 170)

label2 = tkinter.Label(root,font = ('微软雅黑',30),bg = '#EEE9E9',bd ='9',fg = 'black',anchor = 'se',textvariable

= result)

label2.place(y = 170,width = 280,height = 60)

#数字键按钮

btn7 = tkinter.Button(root,text = '7',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('7'))

btn7.place(x = 0,y = 285,width = 70,height = 55)

btn8 = tkinter.Button(root,text = '8',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('8'))

btn8.place(x = 70,y = 285,width = 70,height = 55)

btn9 = tkinter.Button(root,text = '9',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('9'))

btn9.place(x = 140,y = 285,width = 70,height = 55)

btn4 = tkinter.Button(root,text = '4',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('4'))

btn4.place(x = 0,y = 340,width = 70,height = 55)

btn5 = tkinter.Button(root,text = '5',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('5'))

btn5.place(x = 70,y = 340,width = 70,height = 55)

btn6 = tkinter.Button(root,text = '6',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('6'))

btn6.place(x = 140,y = 340,width = 70,height = 55)

btn1 = tkinter.Button(root,text = '1',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('1'))

btn1.place(x = 0,y = 395,width = 70,height = 55)

btn2 = tkinter.Button(root,text = '2',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('2'))

btn2.place(x = 70,y = 395,width = 70,height = 55)

btn3 = tkinter.Button(root,text = '3',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('3'))

btn3.place(x = 140,y = 395,width = 70,height = 55)

btn0 = tkinter.Button(root,text = '0',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda :

pressNum('0'))

btn0.place(x = 70,y = 450,width = 70,height = 55)

#运算符号按钮

btnac = tkinter.Button(root,text = 'AC',bd = 0.5,font = ('黑体',20),fg = 'orange',command = lambda :pressCompute('AC'))

btnac.place(x = 0,y = 230,width = 70,height = 55)

btnback = tkinter.Button(root,text = '←',font = ('微软雅黑',20),fg = '#4F4F4F',bd = 0.5,command = lambda:

pressCompute('b'))

btnback.place(x = 70,y = 230,width = 70,height = 55)

btndivi = tkinter.Button(root,text = '÷',font = ('微软雅黑',20),fg = '#4F4F4F',bd = 0.5,command = lambda:

pressCompute('/'))

btndivi.place(x = 140,y = 230,width = 70,height = 55)

btnmul = tkinter.Button(root,text ='×',font = ('微软雅黑',20),fg = "#4F4F4F",bd = 0.5,command = lambda:

pressCompute('*'))

btnmul.place(x = 210,y = 230,width = 70,height = 55)

btnsub = tkinter.Button(root,text = '-',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda:

pressCompute('-'))

btnsub.place(x = 210,y = 285,width = 70,height = 55)

btnadd = tkinter.Button(root,text = '+',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda:

pressCompute('+'))

btnadd.place(x = 210,y = 340,width = 70,height = 55)

btnequ = tkinter.Button(root,text = '=',bg = 'orange',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command =

lambda :pressEqual())

btnequ.place(x = 210,y = 395,width = 70,height = 110)

btnper = tkinter.Button(root,text = '%',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda:

pressCompute('%'))

btnper.place(x = 0,y = 450,width = 70,height = 55)

btnpoint = tkinter.Button(root,text = '.',font = ('微软雅黑',20),fg = ('#4F4F4F'),bd = 0.5,command = lambda:

pressCompute('.'))

btnpoint.place(x = 140,y = 450,width = 70,height = 55)

#操作函数

lists = []                            #设置一个变量 保存运算数字和符号的列表

isPressSign = False                  #添加一个判断是否按下运算符号的标志,假设默认没有按下按钮

isPressNum = False

#数字函数

def pressNum(num):                   #设置一个数字函数 判断是否按下数字 并获取数字将数字写在显示版上

    global lists                     #全局化lists和按钮状态isPressSign

    global isPressSign

    if isPressSign == False:

        pass

    else:                            #重新将运算符号状态设置为否

        result.set(0)

        isPressSign = False

    #判断界面的数字是否为0

    oldnum = result.get()             #第一步

    if oldnum =='0':                 #如过界面上数字为0 则获取按下的数字

       result.set(num)

    else:                            #如果界面上的而数字不是0  则链接上新按下的数字

        newnum = oldnum + num

        result.set(newnum)            #将按下的数字写到面板中

#运算函数

def pressCompute(sign):

    global lists

    global isPressSign

    num = result.get()              #获取界面数字

    lists.append(num)               #保存界面获取的数字到列表中

    lists.append(sign)              #讲按下的运算符号保存到列表中

    isPressSign = True

    if sign =='AC':                #如果按下的是'AC'按键，则清空列表内容，讲屏幕上的数字键设置为默认数字0

        lists.clear()

        result.set(0)

    if sign =='b':                 #如果按下的是退格‘’，则选取当前数字第一位到倒数第二位

        a = num[0:-1]

        lists.clear()

        result.set(a)

#获取运算结果函数

def pressEqual():

    global lists

    global isPressSign

    curnum = result.get()           #设置当前数字变量，并获取添加到列表

    lists.append(curnum)

    computrStr = ''.join(lists)     #讲列表内容用join命令将字符串链接起来

    endNum = eval(computrStr)       #用eval命令运算字符串中的内容

#    a = str(endNum)

#   b = '='+a                       #给运算结果前添加一个 ‘=’ 显示   不过这样写会有BUG

不能连续运算，这里注释，不要 =

#   c = b[0:10]                     #所有的运算结果取9位数

    result.set(endNum)                   #讲运算结果显示到屏幕1

    result2.set(computrStr)         #将运算过程显示到屏幕2

    lists.clear()                   #清空列表内容

root.mainloop()