作业要求

基于tkinter完成一个简易计算器
1 至少包含+-*/运算
2 能正确计算机结果

参考

https://blog.csdn.net/weixin_42795087/article/details/89931944?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522163920966316780274138563%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fall.%2522%257D&request_id=163920966316780274138563&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_allfirst_rank_ecpm_v1~rank_v31_ecpm-2-89931944.pc_search_result_cache&utm_term=python%E8%AE%A1%E7%AE%97%E6%9C%BA&spm=1018.2226.3001.4187

代码与结果

#coding=utf-8
import tkinter
from functools import partial

def get_input(entry, argu):
    input_data = entry.get()

    if (input_data[-1:] == '+') and (argu == '+'):
        return
    if (input_data[-2:] == '+-') and (argu == '-'):
        return
    if (input_data[-2:] == '--') and (argu in ['-', '+']):
        return
    if (input_data[-2:] == '**') and (argu in ['*', '/']):
        return

    entry.insert("end", argu)

def backspace(entry):
    input_len = len(entry.get())
    entry.delete(input_len - 1)

def clear(entry):
    entry.delete(0, "end")

def calc(entry):
    input_data = entry.get()
    if not input_data:
        return

    clear(entry)

    try:
        output_data = str(eval(input_data))
    except Exception:
        entry.insert("end", "Calculation error")
    else:
        if len(output_data) > 20:
            entry.insert("end", "Value overflow")
        else:
            entry.insert("end", output_data)


if __name__ == '__main__':

    root = tkinter.Tk()
    root.title("Calculator")

    root.resizable(0, 0)

    button_bg = 'orange'
    math_sign_bg = 'DarkTurquoise'
    cal_output_bg = 'YellowGreen'
    button_active_bg = 'gray'

    entry = tkinter.Entry(root, justify="right", font=1)
    entry.grid(row=0, column=0, columnspan=4, padx=10, pady=10)

    def place_button(text, func, func_params, bg=button_bg, **place_params):
        my_button = partial(tkinter.Button, root, bg=button_bg, padx=10, pady=3, activebackground=button_active_bg)
        button = my_button(text=text, bg=bg, command=lambda: func(*func_params))
        button.grid(**place_params)

    place_button('7', get_input, (entry, '7'), row=1, column=0, ipadx=5, pady=5)
    place_button('8', get_input, (entry, '8'), row=1, column=1, ipadx=5, pady=5)
    place_button('9', get_input, (entry, '9'), row=1, column=2, ipadx=5, pady=5)
    place_button('4', get_input, (entry, '4'), row=2, column=0, ipadx=5, pady=5)
    place_button('5', get_input, (entry, '5'), row=2, column=1, ipadx=5, pady=5)
    place_button('6', get_input, (entry, '6'), row=2, column=2, ipadx=5, pady=5)
    place_button('1', get_input, (entry, '1'), row=3, column=0, ipadx=5, pady=5)
    place_button('2', get_input, (entry, '2'), row=3, column=1, ipadx=5, pady=5)
    place_button('3', get_input, (entry, '3'), row=3, column=2, ipadx=5, pady=5)
    place_button('0', get_input, (entry, '0'), row=4, column=0, padx=8, pady=5,
                 columnspan=2, sticky=tkinter.E + tkinter.W + tkinter.N + tkinter.S)
    place_button('.', get_input, (entry, '.'), row=4, column=2, ipadx=7, padx=5, pady=5)

    place_button('+', get_input, (entry, '+'), bg=math_sign_bg, row=1, column=3, ipadx=5, pady=5)
    place_button('-', get_input, (entry, '-'), bg=math_sign_bg, row=2, column=3, ipadx=5, pady=5)
    place_button('*', get_input, (entry, '*'), bg=math_sign_bg, row=3, column=3, ipadx=5, pady=5)
    place_button('/', get_input, (entry, '/'), bg=math_sign_bg, row=4, column=3, ipadx=5, pady=5)

    place_button('<-', backspace, (entry,), row=5, column=0, ipadx=5, padx=5, pady=5)
    place_button('C', clear, (entry,), row=5, column=1, pady=5, ipadx=5)
    place_button('=', calc, (entry,), bg=cal_output_bg, row=5, column=2, ipadx=5, padx=5, pady=5,
                 columnspan=2, sticky=tkinter.E + tkinter.W + tkinter.N + tkinter.S)

    root.mainloop()