python（9）–一个简单的计算器
本次根据python的一些基础实现计算器的简单功能，需要的模块及实现功能：
- tkinter
- math
- 简单运算
import tkinter
import math
class JiSuanQi:
def __init__(self):
self.root = tkinter.Tk()
self.root.title('计算器')
self.root.minsize(230, 250)
self.shownum = tkinter.StringVar()
self.shownum.set('0')
self.presslist = []
self.ispresssign = False
self.issumeql = False
self.issqrt = False
self.setwindow()
self.root.mainloop()
def setwindow(self):
label = tkinter.Label(self.root, textvariable = self.shownum, bg='white', font=('黑体', 15), anchor='e', bd=10)
label.place(x=5, y=20, width=220, height=50)
btn1 = tkinter.Button(self.root, text='7', command=lambda: self.pressnum('7'))
btn1.place(x=5, y=100, width=40, height=25)
btn2 = tkinter.Button(self.root, text='8', command=lambda: self.pressnum('8'))
btn2.place(x=50, y=100, width=40, height=25)
btn3 = tkinter.Button(self.root, text='9', command=lambda: self.pressnum('9'))
btn3.place(x=95, y=100, width=40, height=25)
btndiv = tkinter.Button(self.root, text='/', command=lambda: self.presssign('/'))
btndiv.place(x=140, y=100, width=40, height=25)
btnper = tkinter.Button(self.root, text='c', command=self.clear)
btnper.place(x=185, y=100, width=40, height=25)
btn4 = tkinter.Button(self.root, text='4', command=lambda: self.pressnum('4'))
btn4.place(x=5, y=130, width=40, height=25)
btn5 = tkinter.Button(self.root, text='5', command=lambda: self.pressnum('5'))
btn5.place(x=50, y=130, width=40, height=25)
btn6 = tkinter.Button(self.root, text='6', command=lambda: self.pressnum('6'))
btn6.place(x=95, y=130, width=40, height=25)
btntake = tkinter.Button(self.root, text='*', command=lambda: self.presssign('*'))
btntake.place(x=140, y=130, width=40, height=25)
btndif = tkinter.Button(self.root, text='+/-', command=lambda: self.pressnum('-'))
btndif.place(x=185, y=130, width=40, height=25)
btn7 = tkinter.Button(self.root, text='1', command=lambda: self.pressnum('1'))
btn7.place(x=5, y=160, width=40, height=25)
btn8 = tkinter.Button(self.root, text='2', command=lambda: self.pressnum('2'))
btn8.place(x=50, y=160, width=40, height=25)
btn9 = tkinter.Button(self.root, text='3', command=lambda: self.pressnum('3'))
btn9.place(x=95, y=160, width=40, height=25)
btnsub = tkinter.Button(self.root, text='-', command=lambda: self.presssign('-'))
btnsub.place(x=140, y=160, width=40, height=25)
btnetc = tkinter.Button(self.root, text='=', command=self.sumeql)
btnetc.place(x=185, y=160, width=40, height=55)
btn0 = tkinter.Button(self.root, text='0', command=lambda: self.pressnum('0'))
btn0.place(x=5, y=190, width=85, height=25)
btnback = tkinter.Button(self.root,text = '←',command = self.backspaces)
btnback.place(x = 5,y = 220 ,width=85, height=25)
btnadd = tkinter.Button(self.root, text='+', command=lambda: self.presssign('+'))
btnadd.place(x=140, y=190, width=40, height=25)
btnp = tkinter.Button(self.root, text='.', command=lambda: self.pressnum('.'))
btnp.place(x=95, y=190, width=40, height=25)
btnps = tkinter.Button(self.root, text='√', command= self.sqrs)
btnps.place(x=95, y=220, width=40, height=25)
#开根号
def sqrs(self):
if '-' in self.shownum.get():
self.shownum.set('负数不能开平方')
self.issqrt = True
else:
result = math.sqrt(float(self.shownum.get()))
print(result)
self.shownum.set(result)
self.issqrt = True
# 显示
def pressnum(self,num):
#global ispresssign
#global issumeql
#判断运算结果是否为真
if self.issumeql == True:
self.shownum.set('0')
self.issumeql = False
#判断是否加入了运算符号
elif self.ispresssign == True:
self.shownum.set('0')
self.ispresssign = False
elif self.issqrt == True:
self.shownum.set('0')
self.issqrt = False
# elif self.presslist == []:
# self.shownum.set('0')
self.oldnum = self.shownum.get()
if self.oldnum == '0' and num != '.':
# # 加入小数点
# if num == '.':
# #if oldnum.startswith('0'):
# self.shownum.set(oldnum + num)
# if num in oldnum:
#
# pass
# else:
self.shownum.set(num)
# 加入小数点
elif num == '.' :
#如果已经输入了小数点，那么再输入小数点则无效
if num in self.oldnum:
pass
else:
self.shownum.set(self.oldnum+num)
else:#判断正负号
if num == '-':
if self.oldnum.startswith('-'):
self.shownum.set(self.oldnum[1:])
else:
self.shownum.set('-' + self.oldnum)
else:
self.shownum.set(self.oldnum + num)
# 退格
def backspaces(self):
if self.shownum.get() == '0' and self.shownum.get() == '':
self.shownum.set('0')
return
else:
num = len(self.shownum.get())
if num > 1:
self.oldnum = self.shownum.get()
# print(self.oldnum)
self.oldnum = self.oldnum[0:num - 1]
self.shownum.set(self.oldnum)
else:
self.shownum.set('0')
# 运算过程
def presssign(self,sign):
#global presslist
#global ispresssign
self.oldnum = self.shownum.get()
self.presslist.append(self.oldnum)
# if sign in self.presslist:
#
# self.presslist[1] = sign
#
# else:
self.presslist.append(sign)
self.ispresssign = True
# 运算结果
def sumeql(self):
#global presslist
#global issumeql
self.oldnum = self.shownum.get()
self.presslist.append(self.oldnum)
print(self.presslist)
# unswer = ''.join(self.presslist)
#
# if unswer[-1] in '+-*/':
# unswer = unswer[0:-2]
try:
result = eval(''.join(self.presslist))
self.shownum.set(result)
self.presslist.clear()
self.issumeql = True
except:
self.shownum.set('除数不能为0')
self.presslist.clear()
self.issumeql = True
# 清空操作
def clear(self):
self.shownum.set('0')
j = JiSuanQi()
... prompt'''希望大家能帮助完善
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