20214201 实验二 《Python程序设计》实验报告

学号 2021-2022-2 《Python程序设计》实验二报告

课程：《Python程序设计》
班级： 2142
姓名： 刘嘉铭
学号： 20214201
实验教师：王志强
实验日期：2022年3月31日
必修/选修： 公选课

1.实验内容

• 设计并完成一个完整的应用程序，完成加减乘除模等运算，功能多多益善。
• 考核基本语法、判定语句、循环语句、逻辑运算等知识点

2. 实验过程及结果

在本次试验基础上通过自学tkinter实现简单计算器的程序

1.调用tkinter库

import tkinter as tk

2.配置初始窗口设置

root = tk.Tk()创建tk界面
root.geometry('250x380')设置界面分辨率
root.title('Calculate')设置界面标题

3.配置计算器显示栏

frame_show = tk.Frame(width=300, height=150 ,bg='#dddddd')命名并创建Frame栏并进行初始设置
a = tk.StringVar()初始化字符串a为显示在frame_show上的内容
a.set('0')初始化字符串a的值
show_label = tk.Label(frame_show,textvariable = a, bg = 'white', width=12, height=1, font=("Times New Roman", 20))命名并创建label，其在Frame_show中，字符为a，背景颜色为白色，宽12高1，字体为新罗马且字号20
show_label.pack(padx = 10, pady = 10)pack这个label
frame_show.pack()pack整个Frame_show

4.初始化

calcul = []创建空列表用于最终计算
ispress = False判断是否按下按钮，初始化为空

5.自定义函数改变数值

点击查看代码

def changenumber(num):     # 改变数值
    global ispress     # 声明全局变量，下同
    if ispress == False:
        if a.get() == '0'or a.get() == '00':
            a.set('')
            a.set(num)
        else:
            a.set(a.get()+num)
    else:
        a.set(num)
        ispress = False

6.自定义函数选择运算符

点击查看代码

def operation(sign):     # 选择运算符
    global ispress
    global calcul
    ispress = True
    calcul.append(a.get())
    if sign == '+':
        calcul.append('+')
    elif sign == '-':
        calcul.append('-')
    elif sign == '*':
        calcul.append('*')
    elif sign == '/':
        calcul.append('/')
    elif sign == '%':
        calcul.append('%')
    print(calcul)

7.自定义函数进行计算

点击查看代码

def equal():     # 进行计算
    global calcul
    calcul.append(a.get())
    print(calcul)

    calculstr = ''.join(calcul)
    if calculstr[-1] in'+-*/%':
        calculstr = calculstr[0:-1]
    result = eval(calculstr)
    a.set(result)
    calcul.clear()

8.自定义函数删除字符串

点击查看代码

def delete():     # 删除
    if a.get() == '' or a.get() =='0' or a.get() == '00':
        a.set('0')
        return
    else:
        num = len(a.get())
        if num > 1:
            strnum = a.get()
            strnum = strnum[0:-1]
            a.set(strnum)
        else:
            a.set('0')

9.自定义函数清空

点击查看代码

def clearboard():     # 清空
    global calcul
    calcul = []
    a.set('0')
    ispress = False

10.自定义函数正负颠倒

点击查看代码

def signa():     # 正负颠倒
    strnum = a.get()
    if strnum[0] == '-':
        a.set(strnum[1:])
    elif strnum[0] != '-' and strnum != '0':
        a.set('-'+strnum)

11.自定义函数配置按钮

点击查看代码

# 配置按键符
frame_board = tk.Frame(width = 400, height = 350, bg = '#cccccc')
button_del = tk.Button(frame_board, text = '＜-', width = 5, height = 1, command = delete).grid(row = 0, column = 0)
button_signa = tk.Button(frame_board,text = '±', width = 5, height = 1, command = signa).grid(row = 0, column = 2)
button_clearb = tk.Button(frame_board,text = 'CE', width = 5, height = 1, command = clearboard).grid(row = 0, column = 1)
button_mo = tk.Button(frame_board, text = '%', width = 5, height = 1, command = lambda:operation('%')).grid(row = 0, column = 3)
button_1 = tk.Button(frame_board, text = '1', width = 5, height = 2, command = lambda:changenumber('1')).grid(row = 1, column = 0)
button_2 = tk.Button(frame_board, text = '2', width = 5, height = 2, command = lambda:changenumber('2')).grid(row = 1, column = 1)
button_3 = tk.Button(frame_board, text = '3', width = 5, height = 2, command = lambda:changenumber('3')).grid(row = 1, column = 2)
button_plus = tk.Button(frame_board, text = '+', width = 5, height = 2, command = lambda:operation('+')).grid(row = 1, column = 3)
button_4 = tk.Button(frame_board, text = '4', width = 5, height = 2, command = lambda:changenumber('4')).grid(row = 2, column = 0)
button_5 = tk.Button(frame_board, text = '5', width = 5, height = 2, command = lambda:changenumber('5')).grid(row = 2, column = 1)
button_6 = tk.Button(frame_board, text = '6', width = 5, height = 2, command = lambda:changenumber('6')).grid(row = 2, column = 2)
button_minus = tk.Button(frame_board, text = '-', width = 5, height = 2, command = lambda:operation('-')).grid(row = 2, column = 3)
button_7 = tk.Button(frame_board, text = '7', width = 5, height = 2, command = lambda:changenumber('7')).grid(row = 3, column = 0)
button_8 = tk.Button(frame_board, text = '8', width = 5, height = 2, command = lambda:changenumber('8')).grid(row = 3, column = 1)
button_9 = tk.Button(frame_board, text = '9', width = 5, height = 2, command = lambda:changenumber('9')).grid(row = 3, column = 2)
button_mult = tk.Button(frame_board, text = '*', width = 5, height = 2, command = lambda:operation('*')).grid(row = 3, column = 3)
button_00 = tk.Button(frame_board, text = '00', width = 5, height = 2, command = lambda:changenumber('00')).grid(row = 4, column = 0)
button_0 = tk.Button(frame_board, text = '0', width = 5, height = 2, command = lambda:changenumber('0')).grid(row = 4, column = 1)
button_dot = tk.Button(frame_board, text = '.', width = 5, height = 2, command = lambda:changenumber('.')).grid(row = 4, column = 2)
button_equal = tk.Button(frame_board, text = '=', width = 5, height = 2, command = lambda:equal()).grid(row = 4, column = 3)
frame_board.pack(padx = 10,pady = 10)

12.使该窗口永久显示

root.mainloop()

3. 实验过程中遇到的问题和解决过程

• 问题1：无法进行运算
• 问题1解决方案：需先初始化一个列表，后将数据赋值其中
• 问题2：自定义函数无法改变数值
• 问题2解决方案：缩进问题，判断的逻辑不对。
• ...

其他（感悟、思考等）

Python的内置函数和库功能非常强大，通过调用就能利用一行代码实现较为复杂的算法过程。利用lambda函数对代码进行简化也能使其看起来更加富有可读性。
计算器效果过于简陋和单一，无历史操作的保留等常规计算器拥有的功能，未来还需进一步完善并debug。

实验二码云Gitee地址跳转

参考资料

Tkinter教程