How to Package a Python GUI Application with Dependencies Using PyInstaller

Requirement: The executable should automatically read dependencies from a provided Python package and download them to a specified directory during installation, allowing the user to select the package and target directory.

Step 1: Prepare your project structure Ensure your project follows this layout:

project/
│
├── main.py
├── requirements.txt
└── gui/
    └── assets/
        └── (your GUI assets)

The requirements.txt file should list all required libraries, for example:

numpy
pandas
matplotlib

Step 2: Write main.py This script reads requirements.txt , installs the dependencies into a dependencies folder, and then launches a simple Tkinter GUI.

import tkinter as tk
import subprocess
import sys
import os

def install_dependencies():
    # Get the directory of the current script
    script_dir = os.path.dirname(os.path.abspath(__file__))
    # Specify the target directory for installed packages
    target_dir = os.path.join(script_dir, 'dependencies')
    # Create the directory if it does not exist
    if not os.path.exists(target_dir):
        os.makedirs(target_dir)
    # Path to requirements.txt
    requirements_file = os.path.join(script_dir, 'requirements.txt')
    # Install packages to the target directory
    subprocess.check_call([sys.executable, '-m', 'pip', 'install', '--target', target_dir, '-r', requirements_file])

def run_gui():
    root = tk.Tk()
    root.title("My GUI Application")
    label = tk.Label(root, text="Hello, World!")
    label.pack()
    root.mainloop()

if __name__ == '__main__':
    install_dependencies()
    run_gui()

Step 3: Package the application with PyInstaller Open a command prompt, navigate to the project directory, and run:

pyinstaller --onefile --add-data "requirements.txt;." --add-data "gui/assets:gui/assets" main.py

This command does the following:

--onefile: creates a single executable file.
--add-data "requirements.txt;.": includes the
requirements.txt
file in the bundled resources.
--add-data "gui/assets:gui/assets": includes the GUI assets directory (optional, only needed if you have assets).

Step 4: Test the executable After packaging, you will find the .exe file in the dist/ folder. Running it will automatically detect and install the required libraries, then launch the GUI.

Notes

Make sure requirements.txt contains all necessary libraries.

The target machine must allow pip installations; ensure Python is available.

If any dependencies contain binary components, you may need to build them separately for each target OS or find cross‑platform alternatives.

Following these steps creates a self‑contained Python GUI application that simplifies deployment and improves independence.