157 – asyncio introspection

You can use the asyncio CLI (new in Python 3.14) to inspect/debug running Python processes that use asynchronous tasks. For example, take this tiny example of an asynchronous program in the file my_code.py:

import asyncio

async def main():
    await asyncio.sleep(60)

asyncio.run(main())

If you run the program and the running process has the ID 12345, for example, then you can run

$ python -m asyncio pstree 12345

And you get a tree showing all currently-running asyncio tasks in a hierarchical format:

└── (T) Task-1
    └──  main /path/to/my_code.py:4
        └──  sleep /path/to/python/asyncio/tasks.py:702

The subcommand ps can be used instead of pstree to display this information in a table instead of in a tree.