界面方式:

#coding=utf-8
#by : linhut
from Tkinter import *    #导入Tkinter所有组件
def clear():
    display.set('')
def dele():
    display.set(str(display.get()[:-1]))    #取最后一位前面的,转数字
def call(m):
    content = display.get()+m          #display.get()获得当前内容
    display.set(content)                #display.set() 显示内容
    # 得到 '2+3'
def calee():
    if '=' in display.get():            #判断当前内容是否进行过计算
        con = display.get().split('=')[-1]
    else:
        con = display.get()
    try:
        res =eval(con)     #eval字符可计算
        display.set(con + '=\n' + str(res))
    #得到  2+3=5
    except:
        display.set('Error')
        clear()
def main():
    root = Tk()  # 创建顶层窗口
    root.title('Linhut计算器')
    root.geometry()  #设置界面大小
    global display  #创建一个全局变量
    display=StringVar()    #用来得到和设置显示的内容
    label = Label(root,relief='sunken',borderwidth=3,anchor=SE)
#relief设置边框样式,borderwidth设置边框的宽度,anchor设置pack分配的位置
    label.config(bg='grey',width=25,height=3)
    label['textvariable']  = display
#textvariable显示display变量的内容
    label.grid(row=0,column=0,columnspan = 4)
#columnspan设置用几列来显示该组件
    Button(root,text='C',fg = 'Green',width=3,command=lambda:clear()).grid(row=1,column=0)
    Button(root,text='DEL',width=3,command=lambda:dele()).grid(row=1,column=1)
    Button(root,text='/', width=3, command=lambda: call('/')).grid(row=1, column=2)
    Button(root,text='*', width=3, command=lambda: call('*')).grid(row=1, column=3)
    Button(root,text='-', width=3, command=lambda: call('-')).grid(row=2, column=3)
    Button(root,text='+', width=3, command=lambda: call('+')).grid(row=3, column=3)
    Button(root,text='%', width=3, command=lambda: call('%')).grid(row=4, column=3)
    Button(root,text='.', width=3, command=lambda: call('.')).grid(row=5, column=1)
    Button(root,text='1', width=3, command=lambda: call('1')).grid(row=4, column=0)
    Button(root,text='2', width=3, command=lambda: call('2')).grid(row=4, column=1)
    Button(root,text='3', width=3, command=lambda: call('3')).grid(row=4, column=2)
    Button(root,text='4', width=3, command=lambda: call('4')).grid(row=3, column=0)
    Button(root,text='5', width=3, command=lambda: call('5')).grid(row=3, column=1)
    Button(root,text='6', width=3, command=lambda: call('6')).grid(row=3, column=2)
    Button(root,text='7', width=3, command=lambda: call('7')).grid(row=2, column=0)
    Button(root,text='8', width=3, command=lambda: call('8')).grid(row=2, column=1)
    Button(root,text='9', width=3, command=lambda: call('9')).grid(row=2, column=2)
    Button(root,text='0', width=3, command=lambda: call('0')).grid(row=5, column=0)
    Button(root,text='=', width=3, command=lambda: calee()).grid(row=5, column=2,rowspan=3)
    root.mainloop()  # 显示界面
if __name__ == '__main__':
    main()</pre>

字符方式:

#coding=utf-8
#by : linhut
def jia(x,y):
    return (x+y)
def jian(x,y):
    return (x-y)
def cheng(x,y):
    return (x*y)
def chu(x,y):
    return (x/y)
func_dict = {'+':jia,'-':jian,'*':cheng,'/':chu}
oper_set = {'+','-','*','/'}
#运算符集合
#一行来输入,并且完成单项运算就OK
#2 *     3
#2+3
result = 0
while True:
    mystr = input('请输入你要做的操作:')
    mystr_set = set(mystr.strip())
    #去掉空格 变成集合
    oper = (mystr_set&amp;oper_set).pop()
    #取出运算符
    num1 = int(mystr.split(oper)[0])
    num2 = int(mystr.split(oper)[1])
    result = func_dict[oper](num1,num2)
    print('结果是:',result)

mylist = [1,2,-3]

def getsum(mylist):
    mysum = 0
    for var in mylist:
        mysum += var
    return mysum
def jiajian(*arg):
    res = 0
    for var in arg:
        res += var

#就一步

def chengchu(oper,*arg):
    res = 0
    if oper == '*':
        for var in arg:
            res *= arg
    if oper == '/':
        for var in arg:
            res /= arg