python实现可以保存、可以加粗字体、为文字增加下划线的记事本源码

这里提供一个基于Tkinter库实现的Python记事本源码，支持保存、加粗、下划线等文本样式：

import tkinter as tk
from tkinter import ttk
from tkinter import messagebox
from tkinter.filedialog import asksaveasfilename

class Notepad:
    def __init__(self, master):
        self.master = master
        self.filename = None
        self.bold_on = False
        self.underline_on = False
        self.text = tk.Text(self.master, font=("Calibri", 12))
        self.text.pack(fill="both", expand=True)
        self.text.tag_configure("bold", font=("Calibri", 12, "bold"))
        self.text.tag_configure("underline", font=("Calibri", 12, "underline"))

        # 创建菜单栏
        self.menu_bar = tk.Menu(self.master)
        self.file_menu = tk.Menu(self.menu_bar, tearoff=0)
        self.file_menu.add_command(label="新建", command=self.new_file)
        self.file_menu.add_command(label="打开", command=self.open_file)
        self.file_menu.add_command(label="保存", command=self.save_file)
        self.file_menu.add_separator()
        self.file_menu.add_command(label="退出", command=self.master.quit)
        self.menu_bar.add_cascade(label="文件", menu=self.file_menu)

        self.format_menu = tk.Menu(self.menu_bar, tearoff=0)
        self.format_menu.add_command(label="加粗", command=self.bold)
        self.format_menu.add_command(label="下划线", command=self.underline)
        self.menu_bar.add_cascade(label="格式", menu=self.format_menu)

        self.master.config(menu=self.menu_bar)

    def new_file(self):
        self.filename = None
        self.master.title("无标题 - 记事本")
        self.text.delete(1.0, tk.END)

    def open_file(self):
        self.filename = askopenfilename(defaultextension=".txt", filetypes=[("Text Files", "*.txt"), ("All Files", "*.*")])
        if self.filename:
            self.master.title(self.filename + " - 记事本")
            self.text.delete(1.0, tk.END)
            with open(self.filename, "r") as f:
                self.text.insert(1.0, f.read())

    def save_file(self):
        if not self.filename:
            self.filename = asksaveasfilename(defaultextension=".txt", filetypes=[("Text Files", "*.txt"), ("All Files", "*.*")])
        if self.filename:
            with open(self.filename, "w") as f:
                f.write(self.text.get(1.0, tk.END))
            messagebox.showinfo("保存", "文件已保存！")

    def bold(self):
        start = self.text.index(tk.SEL_FIRST)
        end = self.text.index(tk.SEL_LAST)
        if not self.bold_on:
            self.text.tag_add("bold", start, end)
            self.bold_on = True
        else:
            self.text.tag_remove("bold", start, end)
            self.bold_on = False

    def underline(self):
        start = self.text.index(tk.SEL_FIRST)
        end = self.text.index(tk.SEL_LAST)
        if not self.underline_on:
            self.text.tag_add("underline", start, end)
            self.underline_on = True
        else:
            self.text.tag_remove("underline", start, end)
            self.underline_on = False

root = tk.Tk()
notepad = Notepad(root)
root.mainloop()

这个记事本支持新建、打开、保存文件，以及加粗、下划线等文本样式。你可以根据自己的需要对其进行修改和扩展。