5 Best Ways to Get a String from a Tkinter Filedialog in Python 3

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💡 Problem Formulation: When working with graphical user interfaces in Python, developers may need to obtain file paths from users through dialogs. The popular library Tkinter provides a module named filedialog for this purpose. This article explains how to use the tkinter.filedialog module to get a file path as a string, which is essential for opening, saving, or processing files within a Python application. The goal is to show different methods to present a dialog that allows the user to select a file and then capture the absolute path of that file as a string.

Method 1: Using filedialog.askopenfilename()

This method uses the askopenfilename() function from Tkinter’s filedialog module, which prompts the user with a file open dialog and returns the selected file path as a string.

Here’s an example:

import tkinter as tk
from tkinter import filedialog

root = tk.Tk()
root.withdraw()  # Hide the root window

file_path = filedialog.askopenfilename()
print(file_path)

Output:

/home/user/Documents/example.txt

The code snippet initializes a TK window and hides it, then it immediately opens a file dialog for the user to select a file. Once a file is selected, the absolute path is printed to the console. The root window is hidden because we only want to show the file dialog and not a full GUI window.

Method 2: Using filedialog.askopenfile()

The askopenfile() function opens a file dialog but, in addition to returning the file path, it also opens the file for reading and returns a file object. You can then call the name attribute to get the path as a string.

Here’s an example:

import tkinter as tk
from tkinter import filedialog

root = tk.Tk()
root.withdraw()

file_obj = filedialog.askopenfile(mode='r')
if file_obj:
    file_path = file_obj.name
    file_obj.close()
    print(file_path)

Output:

/home/user/Documents/example.txt

After invoking the askopenfile() function, we check if the user has chosen a file rather than cancelling the dialog. If a file is selected, we get the file path through the file_obj.name, close the file, and print the path. This method gives you both the file object and the path, which can be useful if you need to perform immediate file operations.

Method 3: Customizing Options with askopenfilename()

This method is a variation of the first one, adding customization to the file dialog such as setting the title, initial directory, and file types to provide a better user experience.

Here’s an example:

import tkinter as tk
from tkinter import filedialog

root = tk.Tk()
root.withdraw()

file_path = filedialog.askopenfilename(
    title = "Select a text file",
    initialdir = "/",
    filetypes = (("text files","*.txt"),("all files","*.*"))
)
print(file_path)

Output:

/home/user/Documents/example.txt

The snippet is enhanced with additional arguments to askopenfilename() to customize the dialog’s appearance and functionality. The title is set to “Select a text file”, the dialog opens in the root directory initially, and it filters the view to show only text files or all files. Customizing the dialog helps to guide the user in selecting the correct type of file.

Method 4: Using askopenfilenames() for Multiple Files

When the application requires the selection of multiple files, askopenfilenames() can be used. This opens a file dialog that allows users to select multiple files, returning a tuple of file paths.

Here’s an example:

import tkinter as tk
from tkinter import filedialog

root = tk.Tk()
root.withdraw()

file_paths_tuple = filedialog.askopenfilenames()
file_paths_list = list(file_paths_tuple)
print(file_paths_list)

Output:

['/home/user/Documents/example1.txt', '/home/user/Documents/example2.txt']

With askopenfilenames(), users can select more than one file. The returned file paths are in a tuple, which we convert to a list to work with more easily. This method is beneficial when the user needs to open multiple files at once.

Bonus One-Liner Method 5: Lambda Function with askopenfilename()

A lambda function can be used to create a one-liner for obtaining the file path. While it’s compact, it’s not always recommended for readability reasons unless you’re comfortable with the syntax.

Here’s an example:

import tkinter as tk
from tkinter import filedialog

get_file_path = lambda: filedialog.askopenfilename()
print(get_file_path())

Output:

/home/user/Documents/example.txt

This single line of code, when called, triggers the file dialog and returns the file path. While it seems efficient, it’s often better to write clear and readable code, so use this technique with caution.

Summary/Discussion

  • Method 1: askopenfilename(). Simple and direct. Returns a string. Does not open the file.
  • Method 2: askopenfile(). Opens the file and returns a file object. Best when you need to read the file as well.
  • Method 3: Custom options. Enhances user experience by customizing the dialog. Helps in narrowing down file selection.
  • Method 4: askopenfilenames(). Best for multiple file selection. Returns a tuple of file paths.
  • Method 5: Lambda function. Compact and concise. May sacrifice readability for brevity.