Python 桌面应用开发入门：基于 Tkinter 实现简易计算器

前言

在 Python 生态中，Tkinter 是标准库自带的图形用户界面（GUI）模块。对于初学者而言，它是学习桌面应用程序开发的首选工具，无需安装额外的依赖包即可使用。本文将以构建一个功能完整的简易计算器为例，详细讲解窗口创建、组件布局、事件绑定及逻辑处理等核心知识点。

import tkinter as tk from tkinter import messagebox class Calculator: def __init__(self, root): self.root = root self.root.title("Python 简易计算器") self.root.geometry("300x400+500+200") self.root.resizable(False, False) # 变量存储 self.expression = "" self.result_var = tk.StringVar() self.result_var.set("0") self.setup_ui() def setup_ui(self): # 结果显示区域 display_frame = tk.Frame(self.root, bg="#f0f0f0", height=80) display_frame.pack(fill="x", padx=10, pady=10) self.display_label = tk.Label( display_frame, textvariable=self.result_var, font=("宋体", 24), anchor="e", bg="#ffffff", fg="#333333" ) self.display_label.pack(expand=True, fill="both") # 按钮区域 btn_frame = tk.Frame(self.root) btn_frame.pack(fill="both", expand=True, padx=10, pady=10) buttons = [ ('C', 'clear'), ('←', 'back'), ('/', 'operator'), ('*', 'operator'), ('7', 'num'), ('8', 'num'), ('9', 'num'), ('-', 'operator'), ('4', 'num'), ('5', 'num'), ('6', 'num'), ('+', 'operator'), ('1', 'num'), ('2', 'num'), ('3', 'num'), ('=', 'equal'), ('0', 'num'), ('.', 'num') ] row_idx = 0 col_idx = 0 for text, func_type in buttons: cmd = lambda t=text, f=func_type: self.handle_click(t, f) btn = tk.Button( btn_frame, text=text, width=5, height=2, font=("宋体", 16), relief="flat", command=cmd ) btn.grid(row=row_idx, column=col_idx, padx=5, pady=5, sticky="nsew") if col_idx < 3: col_idx += 1 else: col_idx = 0 row_idx += 1 # 调整最后一行 0 和 . 的宽度 # 实际布局中可根据 grid 配置优化，此处简化处理 def handle_click(self, char, action): if action == 'num': self.append_num(char) elif action == 'operator': self.operator(char) elif action == 'clear': self.clear() elif action == 'back': self.back() elif action == 'equal': self.equal() def append_num(self, num): current = self.result_var.get() if current == "0": self.result_var.set(num) else: self.result_var.set(current + num) self.expression += num def operator(self, op): current = self.result_var.get() if not current or current[-1] in ['+', '-', '*', '/']: return self.result_var.set(current + op) self.expression += op def clear(self): self.result_var.set("0") self.expression = "" def back(self): current = self.result_var.get() if len(current) > 1: new_val = current[:-1] self.result_var.set(new_val) self.expression = self.expression[:-1] else: self.result_var.set("0") self.expression = "" def equal(self): try: # 注意：生产环境中严禁直接使用 eval，存在安全风险 # 建议替换为自定义表达式解析器 result = eval(self.expression) self.result_var.set(str(result)) self.expression = str(result) except ZeroDivisionError: self.result_var.set("错误：除零") self.expression = "" except Exception: self.result_var.set("错误") self.expression = "" if __name__ == "__main__": root = tk.Tk() app = Calculator(root) root.mainloop()

Python 桌面应用开发入门：基于 Tkinter 实现简易计算器