Text_editor.py

from tkinter import *
from tkinter.filedialog import askopenfilename,asksaveasfilename

window = Tk()
window.title("Codingal's Text Editor")
window.geometry("600x500")
window.rowconfigure(0,minsize=800,weight=1)
window.columnconfigure(1,minsize=800,weight=1)

def open_file():
    """Open a file for editing"""
    filepath = askopenfilename(
        filetypes=[("Text Files","*.txt"),("All Files","*.*")]
    )

    if not filepath:
        return
    txt_edit.delete(1.0,END)

    with open(filepath,"r") as input_file:
        text = input_file.read()
        txt_edit.insert(END,text)
        input_file.close()
    window.title(f"Codingal's Text Editor = {filepath}")

def save_file():
    filepath = asksaveasfilename(
        defaultextension="txt",
        filetypes=[("Text Files","*.txt"),("All Files","*.*")],
    )
    if not filepath:
        return
    with open(filepath,"w") as output_file:
        text = txt_edit.get(1.0,END)
        output_file.write(text)
    window.title(f"Codingal's text editor - {filepath}")

txt_edit = Text(window)
fr_buttons = Frame(window,relief=RAISED,bd=2)
btn_open = Button(fr_buttons,text="Open",command=open_file)
btn_save = Button(fr_buttons,text="Save As...",command=save_file)
btn_open.grid(row=0,column=0,sticky="ew",padx=5,pady=5)
btn_save.grid(row=1,column=0,sticky="ew",padx=5)

fr_buttons.grid(row=0,column=0,sticky="ns")
txt_edit.grid(row=0,column=1,sticky="nsew")

window.mainloop()