project3_NeedToLoginCalculator（需要进行登陆确认的计算器）

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下列实现代码说明：
　　下列代码主要是实现计算器功能。由于之前在莫凡老师开设的《用 python 和 tkinter 做简单的窗口视窗》课程当中学习了tkinter的内容，在该课程的结束部分是老师带着做一个关于
登录窗口的小程序。
　　在学习了该课程后，自己又去学习了计算器编写的代码，而后，想着能否把这两个小项目结合寄来，于是，新的一个小项目又诞生了。
　　该程序的功能是在打开计算器程序之前需要进行一个登陆操作。
　　该项目涉及到的前面的project如下：

　　1、class13and14and15_登录窗口 - JY小脚丫 - 博客园

　　　　https://www.cnblogs.com/jyfootprint/p/9571509.html

　　2、project1_calculator（使用tkinter实现python计算器，含有具体过程与注释） - JY小脚丫 - 博客园

　　　 https://www.cnblogs.com/jyfootprint/p/9570951.html

代码如下：

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#!/usr/bin/env python
# -*- coding:utf-8 -*-
# ------------------------------------------------------------
import calculator

import tkinter as tk
from tkinter import messagebox
import pickle

window = tk.Tk()
window.title("登录窗口")
window.maxsize(460, 300)
window.minsize(460, 300)
# welcom image
canvas = tk.Canvas(window, width=500, height=200)
image_file = tk.PhotoImage(file='my_login.gif')
# 10, 0 表示锚点的横，纵位置；     anchor='nw'表示锚点的位置是左上角
image = canvas.create_image(10, 0, anchor='nw', image=image_file)
canvas.pack(side='top')

tk.Label(window, text='username:', font=('黑体', 12)).place(x=60, y=160, anchor='nw')
tk.Label(window, text='password:', font=('黑体', 12)).place(x=60, y=190, anchor='nw')

# 设置存储的变量
username = tk.StringVar()
password = tk.StringVar()
# 设置登录的输入框，并获取信息
entry_username = tk.Entry(window, textvariable=username, width=30).place(x=150, y=160, anchor='nw')
entry_password = tk.Entry(window, textvariable=password, width=30, show='*').place(x=150, y=190, anchor='nw')
# 初始化 username 的信息
username.set('example@python.com')

def usr_login():
    usr_name = username.get()
    usr_password = password.get()
    try:
        with open('usrs_info.pickle', 'rb') as usr_file:
            usrs_info = pickle.load(usr_file)
    except FileNotFoundError:
        usrs_info = {'admin': 'admin'}
        pickle.dump(usrs_info, usr_file)

    if usr_name in usrs_info:
        if usr_password == usrs_info[usr_name]:
            messagebox.showinfo(title='Welcom', message='Welcome to log in! 
'+ usr_name)
            window.destroy()
            calculator.Calculator()
        else:
            messagebox.showerror(title='Error', message='Password Error!
Try again!!')
    else:
        is_sign_up = messagebox.askyesno(title='Ask', message='You have not sign up yet.
Sign up now?')
        if is_sign_up is True:
            usr_sign_up()


def usr_sign_up():
    # 设置窗口
    window_sign_up = tk.Toplevel(window)
    window_sign_up.title('Sign up window')
    window_sign_up.maxsize(460, 180)
    window_sign_up.minsize(460, 180)

    # 设置标签
    tk.Label(window_sign_up, text='username:', font=('黑体', 12)).place(x=30, y=30, anchor='nw')
    tk.Label(window_sign_up, text='password:', font=('黑体', 12)).place(x=30, y=60, anchor='nw')
    tk.Label(window_sign_up, text='confirm password:', font=('黑体', 12)).place(x=30, y=90, anchor='nw')

    # 设置输入框
    # 设置存储的变量
    usr_username = tk.StringVar()
    usr_password1 = tk.StringVar()
    usr_password2 = tk.StringVar()
    # 设置登录的输入框，并获取信息
    usr_entry_username = tk.Entry(window_sign_up, textvariable=usr_username, width=40).place(x=170, y=30, anchor='nw')
    usr_entry_password1 = tk.Entry(window_sign_up, textvariable=usr_password1, width=40, show='*').place(x=170, y=60, anchor='nw')
    usr_entry_password2 = tk.Entry(window_sign_up, textvariable=usr_password2, width=40, show='*').place(x=170, y=90, anchor='nw')
    # 初始化 username 的信息
    usr_username.set('example@python.com')
    def new_sign_up():
        new_name = usr_username.get()
        new_password = usr_password1.get()
        new_password_confirm = usr_password2.get()
        # 打开配置文件，查看注册的信息是否在文件中
        with open('usrs_info.pickle', 'rb') as usr_file:
            exist_usr_info = pickle.load(usr_file)
        # 对比用户名是否已经储存在文件中
        if new_name in exist_usr_info :
            messagebox.showerror(title='Error',message='The user has already signed up!')

        else:
            if new_password != new_password_confirm:
                messagebox.showerror(title='Error', message='Password and confirm password must be the same!')
            else:
                exist_usr_info[new_name] = new_password
                with open('usrs_info.pickle', 'wb') as usr_file:
                    # 写入到文件中
                    pickle.dump(exist_usr_info, usr_file)
                    messagebox.showinfo(title='Welcome', message='You have successfully signed up!')
                    window_sign_up.destroy()


    # 设置注册的按钮
    tk.Button(window_sign_up, text='sign up', command=new_sign_up).place(x=220, y=120, anchor='nw')

tk.Button(text='login', command=usr_login).place(x=170, y=220, anchor='nw')
tk.Button(text='sign up', command=usr_sign_up).place(x=240, y=220, anchor='nw')

window.mainloop()

　　

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上面代码说明：

语句：　　import calculator　
说明：　　calculator　是一个自己编写的一个名称为“calculator.py"文件，是用来实现计算器计算功能程序，该程序的内容见一下转接链接
代码内容如下：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
# ------------------------------------------------------------
# ------------------------------------------------分割线-------------------------------------------------
'''
# ------------------------------------------------------------
# # 7、（完成全部设计）实现基本的计算器功能，补充错误检测, 修改‘C’为清楚功能， '<=='为后退功能
# # # 改动位置位置：    def click_button(self, event):
# ------------------------------------------------------------
'''

class Calculator:
    import tkinter as tk
    import tkinter.messagebox as mbox

    def __init__(self):
        # 生成一个窗口对象
        self.window = self.tk.Tk()
        # 命名窗口对象的显示title
        self.window.title('计算器')
        # 设置窗口的大小 minsize最小   maxsize最大
        self.window.minsize(240, 290)
        self.window.maxsize(240, 290)
        # 是否清空显示框判定参数
        # 设置菜单
        self.set_menu()
        # 设置显示框
        self.label_show = self.tk.Label(text='', anchor='se', font=('黑体', 30), fg='black')
        self.label_show.place(x=0, y=0, width=240,height=80)
        # 设置按钮组件
        self.set_buttons()
        # 将窗口放入主消息队列
        self.window.mainloop()

    def set_menu(self):
        '''
        设置菜单
        :return: None
        '''
        # 创建总菜单
        menubar = self.tk.Menu(self.window)
        # 创建一个下拉菜单，并且加入文件菜单
        filemenu = self.tk.Menu(menubar, tearoff=False)
        # 创建菜单中的选项
        filemenu.add_command(label='退出计算器', command=self.window.quit )

        # print author的函数
        def show_author():
            self.mbox.showinfo(title='作者信息',message='作者：许建荣
联系邮箱：jyfootprint@foxmail.com')

        filemenu.add_command(label='作者信息', command=show_author)
        # 将文件菜单作为下拉菜单添加到总菜单中，并且将命名为操作
        menubar.add_cascade(label='查看', menu=filemenu)
        # 显示总菜单
        self.window.config(menu=menubar)


    def set_buttons(self):
        # 基础坐标,  x0, y0,开始坐标； x_width, y_width 间隔
        x0, y0, x_width, y_width,height = 0, 90, 60, 40, 40
        # 7
        btn7 = self.tk.Button(text='7', bd=2, font='黑体')
        btn7.place(         x=x0,           y=y0,               width=x_width,  height=y_width)
        # 8
        btn8 = self.tk.Button(text='8', bd=2, font='黑体')
        btn8.place(         x=x0+x_width*1, y=y0,               width=x_width,  height=y_width)
        # 9
        btn9 = self.tk.Button(text='9', bd=2, font='黑体')
        btn9.place(         x=x0+x_width*2, y=y0,               width=x_width,  height=y_width)
        # +
        btn_add = self.tk.Button(text='+', bd=2, font='黑体')
        btn_add.place(      x=x0+x_width*3, y=y0,               width=x_width,  height=y_width)

        # 4
        btn4 = self.tk.Button(text='4', bd=2, font='黑体')
        btn4.place(         x=x0,           y=y0+y_width,       width=x_width,  height=y_width)
        # 5
        btn5 = self.tk.Button(text='5', bd=2, font='黑体')
        btn5.place(         x=x0+x_width*1, y=y0+y_width,       width=x_width,  height=y_width)
        # 6
        btn6 = self.tk.Button(text='6', bd=2, font='黑体')
        btn6.place(         x=x0+x_width*2, y=y0+y_width,       width=x_width,  height=y_width)
        # -
        btn_subtract = self.tk.Button(text='-', bd=2, font='黑体')
        btn_subtract.place( x=x0+x_width*3, y=y0+y_width,       width=x_width,  height=y_width)

        # 1
        btn1 = self.tk.Button(text='1', bd=2, font='黑体')
        btn1.place(         x=x0,           y=y0+y_width*2,     width=x_width,  height=y_width)
        # 2
        btn2 = self.tk.Button(text='2', bd=2, font='黑体')
        btn2.place(         x=x0+x_width*1, y=y0+y_width*2,     width=x_width,   height=y_width)
        # 3
        btn3 = self.tk.Button(text='3', bd=2, font='黑体')
        btn3.place(         x=x0+x_width*2, y=y0+y_width*2,     width=x_width,   height=y_width)
        # *
        btn_mutiply = self.tk.Button(text='*', bd=2, font='黑体')
        btn_mutiply.place(  x=x0+x_width*3, y=y0+y_width*2,     width=x_width,   height=y_width)

        # 0
        btn0 = self.tk.Button(text='0', bd=2, font='黑体')
        btn0.place(         x=x0,           y=y0+y_width*3,     width=x_width*2, height=y_width)
        # .
        btn_point = self.tk.Button(text='.', bd=2, font='黑体')
        btn_point.place(    x=x0+x_width*2, y=y0+y_width*3,     width=x_width,   height=y_width)
        # /
        btn_divid = self.tk.Button(text='/', bd=2, font='黑体')
        btn_divid.place(    x=x0+x_width*3, y=y0+y_width*3,     width=x_width,   height=y_width)

        # C后退
        btn_clear = self.tk.Button(  text='C', bd=2, font='黑体')
        btn_clear.place(     x=x0,           y=y0+y_width*4,     width=x_width, height=y_width)

        # C后退
        btn_back = self.tk.Button(  text='<==', bd=2, font='黑体')
        btn_back.place(     x=x0+x_width*1,           y=y0+y_width*4,     width=x_width, height=y_width)

        # =
        btn_equal = self.tk.Button( text='=', bd=2, font='黑体')
        btn_equal.place(    x=x0+x_width*2, y=y0+y_width*4,     width=x_width*2, height=y_width)

        # 绑定Button的点击事件
        btn7.bind_class('Button', '<Button-1>', self.click_button)

    def click_button(self, event):

        # 获取点击的按钮信息信息
        input_event = event.widget['text']
        # 输入的按钮信息显示
        self.label_show['text'] = self.label_show['text'] + input_event
        # 异常捕获
        try:
            # 计算符号
            cal_symbol = ['+', '-', '*', '/']
            # 判定运算符号重复的时候,使用最后输入的符号
            if self.label_show['text'][-1] in cal_symbol and self.label_show['text'][-2] in cal_symbol:
                # 取重复符号前面的内容
                header = self.label_show['text'][:-2]
                footer = self.label_show['text'][-1]
                self.label_show['text'] = header + footer
        except:
            pass

        # 进行普通计算
        if event.widget['text'] == '=':
            # 异常捕获
            try:
                res_bit = 2  # 计算保留的位数
                res = eval(self.label_show['text'][:-1])  # 计算点击 “=” 之前的计算表达式
                # print(type(res))
                self.label_show['text'] = str(round(float(res), res_bit))
            except ZeroDivisionError:
                # 除法时，除数不能为0
                self.mbox.showerror(title='错误', message='除法计算时！除数不能为0！')
            except:
                self.mbox.showerror(title='未知名错误', message='算式错误，请检查！')

        elif event.widget['text'] == '<==':
            # 点击的‘<==’也计算在内，它占3个字符，因此是倒数4位去掉
            back_res = self.label_show['text'][:-4]
            self.label_show['text'] = back_res

        elif event.widget['text'] == 'C':
            # 点击的‘C’也计算在内，因此是倒数2位去掉
            self.label_show['text'] = ''

if __name__=='__main__':
    start = Calculator()