It's more convenient than instant noodles~ Use Python to develop a desktop applet

When working with desktop applications,
is there a moment when
you want to learn desktop application development?
It is recommended that you learn a little about this course and not waste too much time,
because no company will recruit Python programmers to develop desktop programs, right?

Development environment:

• Python 3.6
• Pycharm

code

Interface settings

1. import module

import tkinter as tk

2. instantiate a form object

root = tk.Tk()

3. title

root.title('计算器')

4. size and where it appears

root.geometry("295x280+150+150")

5. transparency

root.attributes("-alpha", 0.9)

6. background

root["background"] = "#ffffff"

7. Label

lable1 = tk.Label(root, textvariable=result_num, width=20, height=2, font=('宋体', 20), justify='left', background='#ffffff', anchor='se')

8. layout

lable1.grid(padx=4, pady=4, row=0, column=0, columnspan=4)

9. button

button_clear = tk.Button(root, text='C', width=5, font=('宋体', 16), relief='flat', background='#C0C0C0', command=lambda: clear())
button_back = tk.Button(root, text='←', width=5, font=('宋体', 16), relief='flat', background='#C0C0C0', command=lambda: back())
button_division = tk.Button(root, text='/', width=5, font=('宋体', 16), relief='flat', background='#C0C0C0', command=lambda: operator('/'))
button_multiplication = tk.Button(root, text='x', width=5, font=('宋体', 16), relief='flat', background='#C0C0C0', command=lambda: operator('*'))

button_clear            .grid(padx=4, row=1, column=0)
button_back             .grid(padx=4, row=1, column=1)
button_division         .grid(padx=4, row=1, column=2)
button_multiplication   .grid(padx=4, row=1, column=3)

button_seven = tk.Button(root, text='7', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('7'))
button_eight = tk.Button(root, text='8', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('8'))
button_nine = tk.Button(root, text='9', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('9'))
button_subtraction = tk.Button(root, text='—', width=5, font=('宋体', 16), relief='flat', background='#C0C0C0', command=lambda: operator('-'))
button_seven        .grid(padx=4, row=2, column=0)
button_eight        .grid(padx=4, row=2, column=1)
button_nine         .grid(padx=4, row=2, column=2)
button_subtraction  .grid(padx=4, row=2, column=3)


button_four = tk.Button(root, text='4', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('4'))
button_four.grid(padx=4, pady=4, row=3, column=0)
button_five = tk.Button(root, text='5', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('5'))
button_five.grid(padx=4, row=3, column=1)
button_six = tk.Button(root, text='6', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('6'))
button_six.grid(padx=4, row=3, column=2)
button_addition = tk.Button(root, text='+', width=5, font=('宋体', 16), relief='flat', background='#C0C0C0', command=lambda: operator('+'))
button_addition.grid(padx=4, row=3, column=3)

button_one = tk.Button(root, text='1', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('1'))
button_one.grid(padx=4, row=4, column=0)
button_two = tk.Button(root, text='2', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('2'))
button_two.grid(padx=4, row=4, column=1)
button_three = tk.Button(root, text='3', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('3'))
button_three.grid(padx=4, row=4, column=2)
button_equal = tk.Button(root, text='=', width=5, height=3, font=('宋体', 16), relief='flat', background='#C0C0C0', command=lambda: equal())
button_equal.grid(padx=4, row=4, rowspan=5, column=3)

button_zero = tk.Button(root, text='0', width=12, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('0'))
button_zero.grid(padx=4, pady=4, row=5, column=0, columnspan=2)
button_decimal = tk.Button(root, text='.', width=5, font=('宋体', 16), relief='flat', background='#FFDEAD', command=lambda: append_num('.'))
button_decimal.grid(padx=4, row=5, column=2)

Now get the interface effect

Features

add numbers

def append_num(i):
    lists.append(i)
    result_num.set(''.join(lists))

select operator symbol

def operator(i):
    if len(lists) > 0:
        if lists[-1] in ['+', '-', '*', '/']:
            lists[-1] = i
        else:
            lists.append(i)
        result_num.set(''.join(lists))

clear

def clear():
    lists.clear()
    result_num.set(0)

backspace

def back():
    del lists[-1]
    result_num.set(lists)

equal sign

def equal():
    a = ''.join(lists)
    end_num = eval(a)
    result_num.set(end_num)
    lists.clear()
    lists.append(str(end_num))

Define a list to collect input content

lists = []
result_num = tk.StringVar()
result_num.set(0)

Finally, run the code, the effect is as follows

Try

the operation first to get the result