Ask a user to select a folder to read the files in Python

The filedialog module in Tkinter provides built-in functions for displaying file and folder selection dialogs. While filedialog.askopenfilename() opens individual files, you can use filedialog.askdirectory() to let users select entire folders and read multiple files.

Selecting a Single File

The basic approach uses askopenfilename() to browse and select a file −

import tkinter as tk
from tkinter import filedialog

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

# Open file dialog
filepath = filedialog.askopenfilename(
    title="Select a text file",
    filetypes=[("Text files", "*.txt"), ("All files", "*.*")]
)

if filepath:
    with open(filepath, 'r') as file:
        content = file.read()
        print(f"File: {filepath}")
        print(f"Content preview: {content[:100]}...")
else:
    print("No file selected")

File: /path/to/selected/file.txt
Content preview: This is the beginning of the file content that was selected by the user...

Selecting a Folder to Read Multiple Files

Use askdirectory() to select a folder and process all files within it −

import tkinter as tk
from tkinter import filedialog
import os

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

# Open folder dialog
folder_path = filedialog.askdirectory(title="Select a folder")

if folder_path:
    print(f"Selected folder: {folder_path}")
    
    # List all files in the folder
    for filename in os.listdir(folder_path):
        file_path = os.path.join(folder_path, filename)
        
        # Process only text files
        if filename.endswith('.txt'):
            try:
                with open(file_path, 'r') as file:
                    content = file.read()
                    print(f"\n--- {filename} ---")
                    print(f"Characters: {len(content)}")
            except Exception as e:
                print(f"Error reading {filename}: {e}")
else:
    print("No folder selected")

Selected folder: /path/to/selected/folder

--- file1.txt ---
Characters: 245

--- file2.txt ---
Characters: 189

GUI Application with File Selection

Here's a complete GUI application that combines both file and folder selection −

import tkinter as tk
from tkinter import filedialog, messagebox
import os

class FileReaderApp:
    def __init__(self, root):
        self.root = root
        self.root.title("File Reader")
        self.root.geometry("600x400")
        
        # Create buttons
        tk.Button(root, text="Select File", command=self.select_file, 
                 font=('Arial', 12)).pack(pady=10)
        
        tk.Button(root, text="Select Folder", command=self.select_folder,
                 font=('Arial', 12)).pack(pady=10)
        
        # Text area to display content
        self.text_area = tk.Text(root, height=20, width=70)
        self.text_area.pack(pady=10, padx=10)
        
    def select_file(self):
        filepath = filedialog.askopenfilename(
            title="Select a file",
            filetypes=[("Text files", "*.txt"), ("All files", "*.*")]
        )
        
        if filepath:
            try:
                with open(filepath, 'r') as file:
                    content = file.read()
                    self.text_area.delete(1.0, tk.END)
                    self.text_area.insert(1.0, f"File: {os.path.basename(filepath)}\n\n{content}")
            except Exception as e:
                messagebox.showerror("Error", f"Cannot read file: {e}")
    
    def select_folder(self):
        folder_path = filedialog.askdirectory(title="Select a folder")
        
        if folder_path:
            self.text_area.delete(1.0, tk.END)
            self.text_area.insert(1.0, f"Folder: {folder_path}\n\n")
            
            txt_files = [f for f in os.listdir(folder_path) if f.endswith('.txt')]
            
            if txt_files:
                self.text_area.insert(tk.END, f"Found {len(txt_files)} text files:\n")
                for filename in txt_files:
                    self.text_area.insert(tk.END, f"? {filename}\n")
            else:
                self.text_area.insert(tk.END, "No text files found in this folder.")

# Create and run the application
if __name__ == "__main__":
    root = tk.Tk()
    app = FileReaderApp(root)
    root.mainloop()

Key Methods Comparison

Conclusion

Use filedialog.askdirectory() to let users select folders for batch file processing. Combine with os.listdir() and file filtering to read specific file types from the selected directory.