py-proc-watch 0.2.1

Pure Python procps "watch" replacement

py-proc-watch

Library and command line tool for watching process output. This is more or less a simpler version of watch from procps.

The main differences come from defaults:

• py-proc-watch always trims long lines so they fit on the screen
• py-proc-watch respects color ANSI escape sequences (but strips the rest)
• Python or C for the implementation

Design goals

py-proc-watch library and tool should be:

1. simple
2. fast for very long output of executed command
3. easily tested for correct behavior
4. pure Python to maximize the amount of supported systems
5. easy to use in other tools

Usage

pywatch command line tool supports only a few command line options to keep it simple:

usage: pywatch.py [-h] [-n INTERVAL] [-p] [-v] command [command ...]

positional arguments:
  command               command to watch, can be specified as a quoted string or as a list (use -- to separate pywatch and command options)

options:
  -h, --help            show this help message and exit
  -n INTERVAL, --interval INTERVAL
                        seconds to wait between command runs, positive floats and zero are accepted
  -p, --precise         try to run the command precisely at intervals
  -v, --debug           show debug information

py_proc_watch can be used also as a Python module to provide "watch-like" functionality easily. The library is quite simple, so just read the source and tests.

Development

py-proc-watch uses Python Poetry to manage dependencies, version 1.3.0 or later is required due to lock file format.

Used tools:

• isort for keeping imports sane
• black for enforcing a consistent code style
• ruff for linting
• mypy for type checking
• pytest for running test
• poethepoet for easily running all of the above

The magic incantation:

poetry run poe check

will run all of the lint and test tools for you. During development running:

poetry run poe format

Will run isort and black to format the source code, ruff and mypy will be executed after code formatting to check for violations.

Contributing and reporting issues

Please use GitHub Issues and Pull requests. If you're contributing code please see Development section.

License

MIT, see LICENSE.md for full text. This is very permissive license, see following pages for more information:

• Open Source Initiative page about MIT license
• tl;drLegal page about MIT license