1. Calculator
1) Case introduction
This example uses Python to develop a graphical calculator that can perform simple four arithmetic operations. The Tkinter graphics component will be used for development. Main knowledge points: Python Tkinter interface programming; calculator logic operation implementation. The difficulty of this example is beginner level and is suitable for users with basic Python and Tkinter component programming knowledge.
2) Design principle
Structurally speaking, a simple graphical interface needs to be composed of interface components, component event listeners (logic to respond to various events) and specific event processing logic. The main work of interface implementation is to create each interface component object, initialize it, and control the hierarchical relationship and layout between each component.
3) Sample effect
4) Sample source code
import tkinter
import math
import tkinter.messagebox
class Calculator(object):
# 界面布局方法
def __init__(self):
# 创建主界面，并且保存到成员属性中
self.root = tkinter.Tk()
self.root.minsize(280, 450)
self.root.maxsize(280, 470)
self.root.title('计算器')
# 设置显式面板的变量
self.result = tkinter.StringVar()
self.result.set(0)
# 设置一个全局变量 运算数字和f符号的列表
self.lists = []
# 添加一个用于判断是否按下运算符号的标志
self.ispresssign = False
# 界面布局
self.menus()
self.layout()
self.root.mainloop()
# 计算器菜单界面摆放
def menus(self):
# 添加菜单
# 创建总菜单
allmenu = tkinter.Menu(self.root)
# 添加子菜单
filemenu = tkinter.Menu(allmenu, tearoff=0)
# 添加选项卡
filemenu.add_command(
label='标准型(T) Alt+1', command=self.myfunc)
filemenu.add_command(
label='科学型(S) Alt+2', command=self.myfunc)
filemenu.add_command(
label='程序员(P) Alt+3', command=self.myfunc)
filemenu.add_command(label='统计信息(A) Alt+4', command=self.myfunc)
# 添加分割线
filemenu.add_separator()
# 添加选项卡
filemenu.add_command(label='历史记录(Y) Ctrl+H', command=self.myfunc)
filemenu.add_command(label='数字分组(I)', command=self.myfunc)
# 添加分割线
filemenu.add_separator()
# 添加选项卡
filemenu.add_command(
label='基本(B) Ctrl+F4', command=self.myfunc)
filemenu.add_command(label='单位转换(U) Ctrl+U', command=self.myfunc)
filemenu.add_command(label='日期计算(D) Ctrl+E', command=self.myfunc)
menu1 = tkinter.Menu(filemenu, tearoff=0)
menu1.add_command(label='抵押(M)', command=self.myfunc)
menu1.add_command(label='汽车租赁(V)', command=self.myfunc)
menu1.add_command(label='油耗(mpg)(F)', command=self.myfunc)
menu1.add_command(label='油耗(l/100km)(U)', command=self.myfunc)
filemenu.add_cascade(label='工作表(W)', menu=menu1)
allmenu.add_cascade(label='查看(V)', menu=filemenu)
# 添加子菜单2
editmenu = tkinter.Menu(allmenu, tearoff=0)
# 添加选项卡
editmenu.add_command(label='复制(C) Ctrl+C', command=self.myfunc)
editmenu.add_command(label='粘贴(V) Ctrl+V', command=self.myfunc)
# 添加分割线
editmenu.add_separator()
# 添加选项卡
menu2 = tkinter.Menu(filemenu, tearoff=0)
menu2.add_command(label='复制历史记录(I)', command=self.myfunc)
menu2.add_command(
label='编辑(E) F2', command=self.myfunc)
menu2.add_command(label='取消编辑(N) Esc', command=self.myfunc)
menu2.add_command(label='清除(L) Ctrl+Shift+D', command=self.myfunc)
editmenu.add_cascade(label='历史记录(H)', menu=menu2)
allmenu.add_cascade(label='编辑(E)', menu=editmenu)
# 添加子菜单3
helpmenu = tkinter.Menu(allmenu, tearoff=0)
# 添加选项卡
helpmenu.add_command(label='查看帮助(V) F1', command=self.myfunc)
# 添加分割线
helpmenu.add_separator()
# 添加选项卡
helpmenu.add_command(label='关于计算器(A)', command=self.myfunc)
allmenu.add_cascade(label='帮助(H)', menu=helpmenu)
self.root.config(menu=allmenu)
# 计算器主界面摆放
def layout(self):
# 显示屏
result = tkinter.StringVar()
result.set(0)
show_label = tkinter.Label(self.root, bd=3, bg='white', font=(
'宋体', 30), anchor='e', textvariable=self.result)
show_label.place(x=5, y=20, width=270, height=70)
# 功能按钮MC
button_mc = tkinter.Button(self.root, text='MC', command=self.wait)
button_mc.place(x=5, y=95, width=50, height=50)
# 功能按钮MR
button_mr = tkinter.Button(self.root, text='MR', command=self.wait)
button_mr.place(x=60, y=95, width=50, height=50)
# 功能按钮MS
button_ms = tkinter.Button(self.root, text='MS', command=self.wait)
button_ms.place(x=115, y=95, width=50, height=50)
# 功能按钮M+
button_mjia = tkinter.Button(self.root, text='M+', command=self.wait)
button_mjia.place(x=170, y=95, width=50, height=50)
# 功能按钮M-
button_mjian = tkinter.Button(self.root, text='M-', command=self.wait)
button_mjian.place(x=225, y=95, width=50, height=50)
# 功能按钮←
button_zuo = tkinter.Button(self.root, text='←', command=self.dele_one)
button_zuo.place(x=5, y=150, width=50, height=50)
# 功能按钮CE
button_ce = tkinter.Button(
self.root, text='CE', command=lambda: self.result.set(0))
button_ce.place(x=60, y=150, width=50, height=50)
# 功能按钮C
button_c = tkinter.Button(self.root, text='C', command=self.sweeppress)
button_c.place(x=115, y=150, width=50, height=50)
# 功能按钮±
button_zf = tkinter.Button(self.root, text='±', command=self.zf)
button_zf.place(x=170, y=150, width=50, height=50)
# 功能按钮√
button_kpf = tkinter.Button(self.root, text='√', command=self.kpf)
button_kpf.place(x=225, y=150, width=50, height=50)
# 数字按钮7
button_7 = tkinter.Button(
self.root, text='7', command=lambda: self.pressnum('7'))
button_7.place(x=5, y=205, width=50, height=50)
# 数字按钮8
button_8 = tkinter.Button(
self.root, text='8', command=lambda: self.pressnum('8'))
button_8.place(x=60, y=205, width=50, height=50)
# 数字按钮9
button_9 = tkinter.Button(
self.root, text='9', command=lambda: self.pressnum('9'))
button_9.place(x=115, y=205, width=50, height=50)
# 功能按钮/
button_division = tkinter.Button(
self.root, text='/', command=lambda: self.presscalculate('/'))
button_division.place(x=170, y=205, width=50, height=50)
# 功能按钮%
button_remainder = tkinter.Button(
self.root, text='//', command=lambda: self.presscalculate('//'))
button_remainder.place(x=225, y=205, width=50, height=50)
# 数字按钮4
button_4 = tkinter.Button(
self.root, text='4', command=lambda: self.pressnum('4'))
button_4.place(x=5, y=260, width=50, height=50)
# 数字按钮5
button_5 = tkinter.Button(
self.root, text='5', command=lambda: self.pressnum('5'))
button_5.place(x=60, y=260, width=50, height=50)
# 数字按钮6
button_6 = tkinter.Button(
self.root, text='6', command=lambda: self.pressnum('6'))
button_6.place(x=115, y=260, width=50, height=50)
# 功能按钮*
button_multiplication = tkinter.Button(
self.root, text='*', command=lambda: self.presscalculate('*'))
button_multiplication.place(x=170, y=260, width=50, height=50)
# 功能按钮1/x
button_reciprocal = tkinter.Button(
self.root, text='1/x', command=self.ds)
button_reciprocal.place(x=225, y=260, width=50, height=50)
# 数字按钮1
button_1 = tkinter.Button(
self.root, text='1', command=lambda: self.pressnum('1'))
button_1.place(x=5, y=315, width=50, height=50)
# 数字按钮2
button_2 = tkinter.Button(
self.root, text='2', command=lambda: self.pressnum('2'))
button_2.place(x=60, y=315, width=50, height=50)
# 数字按钮3
button_3 = tkinter.Button(
self.root, text='3', command=lambda: self.pressnum('3'))
button_3.place(x=115, y=315, width=50, height=50)
# 功能按钮-
button_subtraction = tkinter.Button(
self.root, text='-', command=lambda: self.presscalculate('-'))
button_subtraction.place(x=170, y=315, width=50, height=50)
# 功能按钮=
button_equal = tkinter.Button(
self.root, text='=', command=lambda: self.pressequal())
button_equal.place(x=225, y=315, width=50, height=105)
# 数字按钮0
button_0 = tkinter.Button(
self.root, text='0', command=lambda: self.pressnum('0'))
button_0.place(x=5, y=370, width=105, height=50)
# 功能按钮.
button_point = tkinter.Button(
self.root, text='.', command=lambda: self.pressnum('.'))
button_point.place(x=115, y=370, width=50, height=50)
# 功能按钮+
button_plus = tkinter.Button(
self.root, text='+', command=lambda: self.presscalculate('+'))
button_plus.place(x=170, y=370, width=50, height=50)
# 计算器菜单功能
def myfunc(self):
tkinter.messagebox.showinfo('', '预留接口，学成之后，你是不是有冲动添加该功能.')
# 数字方法
def pressnum(self, num):
# 全局化变量
# 判断是否按下了运算符号
if self.ispresssign == False:
pass
else:
self.result.set(0)
# 重置运算符号的状态
self.ispresssign = False
if num == '.':
num = '0.'
# 获取面板中的原有数字
oldnum = self.result.get()
# 判断界面数字是否为0
if oldnum == '0':
self.result.set(num)
else:
# 连接上新按下的数字
newnum = oldnum + num
# 将按下的数字写到面板中
self.result.set(newnum)
# 运算函数
def presscalculate(self, sign):
# 保存已经按下的数字和运算符号
# 获取界面数字
num = self.result.get()
self.lists.append(num)
# 保存按下的操作符号
self.lists.append(sign)
# 设置运算符号为按下状态
self.ispresssign = True
# 获取运算结果
def pressequal(self):
# 获取所有的列表中的内容（之前的数字和操作）
# 获取当前界面上的数字
curnum = self.result.get()
# 将当前界面的数字存入列表
self.lists.append(curnum)
# 将列表转化为字符串
calculatestr = ''.join(self.lists)
# 使用eval执行字符串中的运算即可
endnum = eval(calculatestr)
# 将运算结果显示在界面中
self.result.set(str(endnum)[:10])
if self.lists != 0:
self.ispresssign = True
# 清空运算列表
self.lists.clear()
# 暂未开发说明
def wait(self):
tkinter.messagebox.showinfo('', '更新中......')
# ←按键功能
def dele_one(self):
if self.result.get() == '' or self.result.get() == '0':
self.result.set('0')
return
else:
num = len(self.result.get())
if num > 1:
strnum = self.result.get()
strnum = strnum[0:num - 1]
self.result.set(strnum)
else:
self.result.set('0')
# ±按键功能
def zf(self):
strnum = self.result.get()
if strnum[0] == '-':
self.result.set(strnum[1:])
elif strnum[0] != '-' and strnum != '0':
self.result.set('-' + strnum)
# 1/x按键功能
def ds(self):
dsnum = 1 / int(self.result.get())
self.result.set(str(dsnum)[:10])
if self.lists != 0:
self.ispresssign = True
# 清空运算列表
self.lists.clear()
# C按键功能
def sweeppress(self):
self.lists.clear()
self.result.set(0)
# √按键功能
def kpf(self):
strnum = float(self.result.get())
endnum = math.sqrt(strnum)
if str(endnum)[-1] == '0':
self.result.set(str(endnum)[:-2])
else:
self.result.set(str(endnum)[:10])
if self.lists != 0:
self.ispresssign = True
# 清空运算列表
self.lists.clear()
# 实例化对象
my_calculator = Calculator()
2. Notepad
1) Case introduction
tkinter is a graphical interface interface library for tk under Python, which can facilitate graphical interface design and interactive operation programming. The advantages of tkinter are that it is easy to use and well integrated with Python. tkinter is integrated by default under Python 3.
The Python version used in this example is 3.8. If you want to use tkinter under python 2.x, please install it first. It should be noted that the usage of tkinter under different Python versions may be slightly different. It is recommended to use the Python3.x version. The difficulty of this example is intermediate, suitable for users with basic Python and Tkinter component programming knowledge.
2) Example effect
3) Sample source code
from tkinter import *
from tkinter.filedialog import *
from tkinter.messagebox import *
import os
filename = ""
def author():
showinfo(title="作者", message="Python")
def power():
showinfo(title="版权信息", message="课堂练习")
def mynew():
global top, filename, textPad
top.title("未命名文件")
filename = None
textPad.delete(1.0, END)
def myopen():
global filename
filename = askopenfilename(defaultextension=".txt")
if filename == "":
filename = None
else:
top.title("记事本" + os.path.basename(filename))
textPad.delete(1.0, END)
f = open(filename, 'r')
textPad.insert(1.0, f.read())
f.close()
def mysave():
global filename
try:
f = open(filename, 'w')
msg = textPad.get(1.0, 'end')
f.write(msg)
f.close()
except:
mysaveas()
def mysaveas():
global filename
f = asksaveasfilename(initialfile="未命名.txt", defaultextension=".txt")
filename = f
fh = open(f, 'w')
msg = textPad.get(1.0, END)
fh.write(msg)
fh.close()
top.title("记事本 " + os.path.basename(f))
def cut():
global textPad
textPad.event_generate("<<Cut>>")
def copy():
global textPad
textPad.event_generate("<<Copy>>")
def paste():
global textPad
textPad.event_generate("<<Paste>>")
def undo():
global textPad
textPad.event_generate("<<Undo>>")
def redo():
global textPad
textPad.event_generate("<<Redo>>")
def select_all():
global textPad
# textPad.event_generate("<<Cut>>")
textPad.tag_add("sel", "1.0", "end")
def find():
t = Toplevel(top)
t.title("查找")
t.geometry("260x60+200+250")
t.transient(top)
Label(t, text="查找：").grid(row=0, column=0, sticky="e")
v = StringVar()
e = Entry(t, width=20, textvariable=v)
e.grid(row=0, column=1, padx=2, pady=2, sticky="we")
e.focus_set()
c = IntVar()
Checkbutton(t, text="不区分大小写", variable=c).grid(row=1, column=1, sticky='e')
Button(t, text="查找所有", command=lambda: search(v.get(), c.get(),
textPad, t, e)).grid(row=0, column=2, sticky="e" + "w", padx=2,
pady=2)
def close_search():
textPad.tag_remove("match", "1.0", END)
t.destroy()
t.protocol("WM_DELETE_WINDOW", close_search)
def mypopup(event):
# global editmenu
editmenu.tk_popup(event.x_root, event.y_root)
def search(needle, cssnstv, textPad, t, e):
textPad.tag_remove("match", "1.0", END)
count = 0
if needle:
pos = "1.0"
while True:
pos = textPad.search(needle, pos, nocase=cssnstv, stopindex=END)
if not pos:
break
lastpos = pos + str(len(needle))
textPad.tag_add("match", pos, lastpos)
count += 1
pos = lastpos
textPad.tag_config('match', fg='yellow', bg="green")
e.focus_set()
t.title(str(count) + "个被匹配")
top = Tk()
top.title("记事本")
top.geometry("600x400+100+50")
menubar = Menu(top)
# 文件功能
filemenu = Menu(top)
filemenu.add_command(label="新建", accelerator="Ctrl+N", command=mynew)
filemenu.add_command(label="打开", accelerator="Ctrl+O", command=myopen)
filemenu.add_command(label="保存", accelerator="Ctrl+S", command=mysave)
filemenu.add_command(label="另存为", accelerator="Ctrl+shift+s", command=mysaveas)
menubar.add_cascade(label="文件", menu=filemenu)
# 编辑功能
editmenu = Menu(top)
editmenu.add_command(label="撤销", accelerator="Ctrl+Z", command=undo)
editmenu.add_command(label="重做", accelerator="Ctrl+Y", command=redo)
editmenu.add_separator()
editmenu.add_command(label="剪切", accelerator="Ctrl+X", command=cut)
editmenu.add_command(label="复制", accelerator="Ctrl+C", command=copy)
editmenu.add_command(label="粘贴", accelerator="Ctrl+V", command=paste)
editmenu.add_separator()
editmenu.add_command(label="查找", accelerator="Ctrl+F", command=find)
editmenu.add_command(label="全选", accelerator="Ctrl+A", command=select_all)
menubar.add_cascade(label="编辑", menu=editmenu)
# 关于 功能
aboutmenu = Menu(top)
aboutmenu.add_command(label="作者", command=author)
aboutmenu.add_command(label="版权", command=power)
menubar.add_cascade(label="关于", menu=aboutmenu)
top['menu'] = menubar
# shortcutbar = Frame(top, height=25, bg='light sea green')
# shortcutbar.pack(expand=NO, fill=X)
# Inlabe = Label(top, width=2, bg='antique white')
# Inlabe.pack(side=LEFT, anchor='nw', fill=Y)
textPad = Text(top, undo=True)
textPad.pack(expand=YES, fill=BOTH)
scroll = Scrollbar(textPad)
textPad.config(yscrollcommand=scroll.set)
scroll.config(command=textPad.yview)
scroll.pack(side=RIGHT, fill=Y)
# 热键绑定
textPad.bind("<Control-N>", mynew)
textPad.bind("<Control-n>", mynew)
textPad.bind("<Control-O>", myopen)
textPad.bind("<Control-o>", myopen)
textPad.bind("<Control-S>", mysave)
textPad.bind("<Control-s>", mysave)
textPad.bind("<Control-A>", select_all)
textPad.bind("<Control-a>", select_all)
textPad.bind("<Control-F>", find)
textPad.bind("<Control-f>", find)
textPad.bind("<Button-3>", mypopup)
top.mainloop()