Python Watchgod

Introduction

Python Watchgod is a Python package that allows you to watch a directory for file changes and execute a command, function, or script in response to the changes. It can monitor changes to all files or a specific set of files in a given directory.

This package is especially useful for developers who need to automatically run tests, build scripts or other custom scripts when changes are made to their code.

Installation

You can install Python Watchgod using pip:

!pip install watchgod

Usage

The basic usage of Python Watchgod is to provide a directory to watch and a command to execute in response to changes.

Here's an example that will watch for changes to all files in the current directory and execute a command each time a change is detected:

import watchgod
import subprocess

def execute_on_change():
    subprocess.run(['echo', 'Directory has changed!'])

watchgod.watch('.', execute_on_change)

In this example, we import both the watchgod package and the subprocess package to execute a shell command. We then define a function that will be called every time a change is detected. We use the subprocess package to execute the 'echo' command with the message 'Directory has changed!'.

Finally, we call the watch() function from the watchgod package, passing it the directory to watch and the function to execute on changes.

Watching specific files

You can also watch specific files by passing a list of filenames or file extensions to the watch() function:

import watchgod

def execute_on_change():
    print('File has changed!')

watchgod.watch('.', execute_on_change, watcher_cls=watchgod.DefaultWatcher, watcher_kwargs=dict(filenames=['file.py']))

In this example, we watch only for changes to a single file named 'file.py'. The execute_on_change function will only be called when changes are made to this file.

Conclusion

Python Watchgod is a very useful tool for automatically running your custom scripts when changes are made to your code. It can save you a lot of time and make your development process much more efficient. Give it a try today!