---

import tkinter as tk


def add_digit(digit):
    value = entry.get() + str(digit)
    entry.delete(0, 'end')
    entry.insert('end', value)


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


def calculate():
    try:
        result = eval(entry.get())

        if int(result) == float(result):
            result = int(result)

        entry.delete(0, 'end')
        entry.insert('end', result)

    except Exception:
        entry.delete(0, 'end')
        entry.insert('end', 'Ошибка!')


root = tk.Tk()
root.title('Калькулятор')
root.geometry('280x360')
root.resizable(False, False)

entry = tk.Entry(root, justify='right', font='Arial 14 bold')
entry.grid(row=0, column=0, columnspan=4, sticky='we', padx=5, pady=5)

buttons = [
    ('7', 1, 0),
    ('8', 1, 1),
    ('9', 1, 2),
    ('/', 1, 3),

    ('4', 2, 0),
    ('5', 2, 1),
    ('6', 2, 2),
    ('*', 2, 3),

    ('1', 3, 0),
    ('2', 3, 1),
    ('3', 3, 2),
    ('-', 3, 3),

    ('C', 4, 0),
    ('0', 4, 1),
    ('=', 4, 2),
    ('+', 4, 3)
]

for btn_text, row, col in buttons:
    def on_click(text=btn_text):
        if text.isdigit():
            add_digit(int(text))
        elif text == '=':
            calculate()
        elif text == 'C':
            clear()
        else:
            entry.insert('end', text)


    button = tk.Button(
        root, text=btn_text, bd=3, relief='raised',
        command=on_click, font='Arial 14'
    )
    button.grid(row=row, column=col, stick='wens', padx=5, pady=5)

for i in range(4):
    root.grid_rowconfigure(i, weight=1)
for j in range(4):
    root.grid_columnconfigure(j, weight=1)

root.mainloop()