用Python写一个简单的计算器

import tkinter as a
root = a.Tk() #创建一个主窗口，用于容纳整个GUI程序
root.minsize(300,511)
root.title(‘欢迎您使用本计算器’)
#result为结果显示区域，result2为运算过程显示区域，anchor 指示文字会被放在控件的什么位置, 此为放到右下
result = a.StringVar()
result.set(’’)
result2 = a.StringVar()
result2.set(’’)
label = a.Label(root,font = (’//Library//Fonts//Hanzipen.ttc’,22),bg=‘black’,bd=‘9’,fg=‘white’,anchor=‘se’,textvariable=result2)
label.place(width = 300,height = 73)
label2 = a.Label(root,font = (’//Library//Fonts//Hanzipen.ttc’,22),bg=‘black’,bd=‘9’,fg=‘white’,anchor=‘se’,textvariable=result)
label2.place(y = 73,width = 300,height = 73)
#以下为按钮区域
#页面第一行按钮
buttonAC = a.Button(root,text = ‘AC’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressCompute(‘AC’))
buttonAC.place(x = 0,y = 146,width = 75,height = 73)
buttonDel = a.Button(root,text = ‘DEL’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressCompute(‘del’))
buttonDel.place(x = 75,y = 146,width = 75,height = 73)
buttonYu= a.Button(root,text = ‘%’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressCompute(’%’))
buttonYu.place(x = 150,y = 146,width = 75,height = 73)
buttonChu= a.Button(root,text=‘÷’,bg = ‘orange’,font = (’//Library//Fonts//Hanzipen.ttc’,22),highlightbackground="#FF7F24",bd=‘0.5’,fg=’#4F4F4F’,command = lambda : pressCompute(’/’))
buttonChu.place(x = 225,y = 146,width = 75,height = 73)
#页面第二行按钮
button7 = a.Button(root,text = ‘7’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘7’))
button7.place(x = 0,y = 219,width = 75,height = 73)
button8 = a.Button(root,text = ‘8’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘8’))
button8.place(x = 75,y = 219,width = 75,height = 73)
button9 = a.Button(root,text = ‘9’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘9’))
button9.place(x = 150,y = 219,width = 75,height = 73)
buttonCheng= a.Button(root,text = ‘×’,bg = ‘orange’,font = (’//Library//Fonts//Hanzipen.ttc’,22),highlightbackground="#FF7F24",fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressCompute(’*’))
buttonCheng.place(x = 225,y = 219,width = 75,height = 73)
#页面第三行按钮
button4 = a.Button(root,text = ‘4’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘4’))
button4.place(x = 0,y = 292,width = 75,height = 73)
button5 = a.Button(root,text = ‘5’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘5’))
button5.place(x = 75,y = 292,width = 75,height = 73)
button6 = a.Button(root,text = ‘6’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘6’))
button6.place(x = 150,y = 292,width = 75,height = 73)
buttonJian= a.Button(root,text = ‘-’,bg = ‘orange’,font = (’//Library//Fonts//Hanzipen.ttc’,22),highlightbackground="#FF7F24",fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressCompute(’-’))
buttonJian.place(x = 225,y = 292,width = 75,height = 73)
#页面第四行按钮
button1 = a.Button(root,text = ‘1’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘1’))
button1.place(x = 0,y = 365,width = 75,height = 73)
button2 = a.Button(root,text = ‘2’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘2’))
button2.place(x = 75,y = 365,width = 75,height = 73)
button3 = a.Button(root,text = ‘3’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘3’))
button3.place(x = 150,y = 365,width = 75,height = 73)
buttonJia= a.Button(root,text = ‘+’,bg = ‘orange’,font = (’//Library//Fonts//Hanzipen.ttc’,22),highlightbackground="#FF7F24",fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressCompute(’+’))
buttonJia.place(x = 225,y = 365,width = 75,height = 73)
#页面第五行按钮
button0 = a.Button(root,text = ‘0’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(‘0’))
button0.place(x = 0,y = 438,width = 150,height = 73)
buttonDian= a.Button(root,text = ‘.’,font = (’//Library//Fonts//Hanzipen.ttc’,22),fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressNum(’.’))
buttonDian.place(x = 150,y = 438,width = 75,height = 73)
buttonDeng= a.Button(root,text = ‘=’,bg = ‘orange’,font = (’//Library//Fonts//Hanzipen.ttc’,22),highlightbackground="#FF7F24",fg = (’#4F4F4F’),bd = 0.5,command = lambda : pressEqual())
buttonDeng.place(x = 225,y = 438,width = 75,height = 73)
#以下为函数
lists = [] #用来保存运算数值
IsPress1 = False #按下运算符的变量
IsPress2 = False #按下数字键的变量
flag = 0 #用来检测‘-’是不是第一个按下
def pressNum(num):
global lists
global IsPress1
global IsPress2
global flag
oldnum=result.get()
if oldnum == ‘0’:
result.set(num)
else:
newnum = oldnum + num #将字符串连接起来
result.set(newnum)
IsPress2 = True
#运算函数
def pressCompute(sign):
global lists
global IsPress1
global flag
num2 = result.get()
if flag1:
num2 = ‘-’+num2
elif IsPress2 == False and sign == ‘-’ : #第一次按下’-'键
flag+=1
return
elif sign’del’:
a=num2[0:-1]
lists.clear()
result.set(a)
return
lists.append(num2) #加到lists列表中
lists.append(sign)
IsPress1 == True
if sign ==‘AC’:
lists.clear()
result.set(0)
result2.set(’’)
flag=0
result.set(’’)
#运算结果显示函数
def pressEqual():
global lists
global IsPress1
global flag
nownum = result.get() #获取当前数字变量
lists.append(nownum)
computrStr = ‘’.join(lists) #讲列表内容用join命令给字符串链接起来
try:
endNum = eval(computrStr) #endNum为浮点数
except:
result.set(‘Syntax ERROR!’) #我的得力科学计算器出错了是这样显示的
#当数字大于14位时候显示不完全
if endNum>9999999999:
result2.set(’’)
result.set(‘Syntax ERROR!’)
return
else:
result.set(round(endNum,6)) #endNum保留六位小数
result2.set(computrStr) #result2显示运算过程在
flag=0
root.mainloop()