Saving data into a file

Apart from selecting existing files and directories, it is also possible to create a new file using Tkinter dialogs. They can be used to persist data generated by our application, letting users choose the name and location of the new file.

Getting ready

We will use the Save file dialog to write the contents of a Text widget into a plain text file:

How to do it...

To open a dialog to save a file, we call the asksaveasfile function from the tkinter.filedialog module. It internally creates a file object with the 'w' mode for writing, or None if the dialog is dismissed:

import tkinter as tk
import tkinter.filedialog as fd

class App(tk.Tk):
    def __init__(self):
        super().__init__()
        self.text = tk.Text(self, height=10, width=50)
        self.btn_save = tk.Button(self, text="Save",
                                  command=self.save_file)

        self.text.pack()
        self.btn_save.pack(pady=10, ipadx=5)

    def save_file(self):
        contents = self...