Watcher

A Python package for monitoring file system changes.

Installation

pip install watcher-fs

Command line usage

See: https://pavelkrupala.github.io/watcher-fs/command_line.html

Synchronous Usage

from watcher_fs.watcher import Watcher, TriggerType
from pathlib import Path 

test_dir = Path("test_dir")

def on_change_simple():
    print(f"Something changed.")

def on_change(change):
    print(f"File {change}")

watcher = Watcher()

# register as glob pattern
watcher.register("test_dir/**/*.txt", on_change_simple, TriggerType.PER_FILE)
watcher.register("test_dir/**/*.py", on_change, TriggerType.ANY_FILE, callback_extra=True)

# register as list of specified files
watcher.register([
    test_dir / "skin.styl",
    test_dir / "styl/default.styl",
    test_dir / "styl/utils.styl"
], on_change, TriggerType.ANY_FILE, callback_extra=True)

# Simulate a check
watcher.check()

# do something
with open(test_dir / "aaa.txt", "w") as f:
    f.write("Modified content")
with open(test_dir / "bbb.txt", "w") as f:
    f.write("Modified content")

with open(test_dir / "skin.styl", "w") as f:
    f.write("a = #0af")
with open(test_dir / "styl/default.styl", "w") as f:
    f.write("a = #f00")

# check again
watcher.check()

Asynchronous Usage

import asyncio
from pathlib import Path 
from watcher_fs.async_watcher import AsyncWatcher, TriggerType


# Example usage:
async def main():
    test_dir = Path("test_dir")

    async def on_change_simple():  # CHANGED: Async callback
        print(f"Something changed.")

    async def on_change(change):  # CHANGED: Async callback
        print(f"File {change}")

    def create_test_files(file_names):
        """Helper to create test files (synchronous for simplicity)."""
        for file_name in file_names:
            file_path = test_dir / file_name
            file_path.parent.mkdir(parents=True, exist_ok=True)
            with open(file_path, "w") as f:
                if file_name.endswith(".txt"):
                    f.write("Initial content")
                else:  # .styl
                    f.write("a = #fa0")

    create_test_files(["aaa.txt", "bbb.txt", "ccc.txt"])
    create_test_files(["skin.styl", "styl/default.styl", "styl/utils.styl"])

    watcher = AsyncWatcher()
    await watcher.register("test_dir/**/*.txt", on_change_simple, TriggerType.PER_FILE)
    await watcher.register(
        [test_dir / "skin.styl", test_dir / "styl/default.styl", test_dir / "styl/utils.styl"],
        on_change, TriggerType.ANY_FILE, callback_extra=True
    )

    # Simulate a check
    await watcher.check()

    # Modify files (synchronous for simplicity)
    with open(test_dir / "aaa.txt", "w") as f:
        f.write("Modified content")
    with open(test_dir / "bbb.txt", "w") as f:
        f.write("Modified content")
    with open(test_dir / "skin.styl", "w") as f:
        f.write("a = #0af")
    with open(test_dir / "styl/default.styl", "w") as f:
        f.write("a = #f00")

    # Check again
    await watcher.check()


if __name__ == "__main__":
    asyncio.run(main())

Documentation

See https://pavelkrupala.github.io/watcher-fs