Calculator GUI project (code) in Python

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Python GUI Calculator (Smart Version)

import tkinter as tk

def press(num):
    current = entry.get()

    if current == "0":
        if num in "0123456789":
            entry.delete(0, tk.END)
            entry.insert(0, str(num))
        else:
            entry.insert(tk.END, str(num))
    else:
        last_char = current[-1]
        if last_char in "+-*/" and num == "0":
            entry.insert(tk.END, str(num))
        elif current[-2:] in ("+0", "-0", "*0", "/0") and num in "123456789":
            entry.delete(len(current)-1, tk.END)
            entry.insert(tk.END, str(num))
        else:
            entry.insert(tk.END, str(num))

def equal():
    expression = entry.get()
    if expression.strip() == "":
        entry.delete(0, tk.END)
        entry.insert(0, "Error")
        return
    try:
        result = eval(expression)
        if isinstance(result, float) and result.is_integer():
            result = int(result)
        entry.delete(0, tk.END)
        entry.insert(0, str(result))
    except Exception:
        entry.delete(0, tk.END)
        entry.insert(0, "Error")

def clear():
    entry.delete(0, tk.END)
    entry.insert(0, "0")

root = tk.Tk()
root.title("Smart Calculator")
root.geometry("360x450")
root.resizable(False, False)

entry = tk.Entry(root, font=("Arial", 24), bd=10, relief=tk.RIDGE, justify="right")
entry.grid(row=0, column=0, columnspan=4, sticky="nsew", padx=10, pady=10)
entry.insert(0, "0")

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

for (text, row, col) in buttons:
    if text == '=':
        btn = tk.Button(root, text=text, font=("Arial", 18), bg="#4CAF50", fg="white",
                        command=equal)
    else:
        btn = tk.Button(root, text=text, font=("Arial", 18),
                        command=lambda t=text: press(t))
    btn.grid(row=row, column=col, sticky="nsew", padx=5, pady=5)

clear_btn = tk.Button(root, text='C', font=("Arial", 18), bg="#f44336", fg="white", command=clear)
clear_btn.grid(row=5, column=0, columnspan=4, sticky="nsew", padx=10, pady=10)

for i in range(6):
    root.grid_rowconfigure(i, weight=1)
for i in range(4):
    root.grid_columnconfigure(i, weight=1)

root.mainloop()