https://github.com/oconnor663/duct.py

a Python library for running child processes
https://github.com/oconnor663/duct.py

Last synced: 12 days ago
JSON representation

a Python library for running child processes

• Host: GitHub
• URL: https://github.com/oconnor663/duct.py
• Owner: oconnor663
• License: mit
• Created: 2015-08-20T03:06:30.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2024-04-18T19:55:10.000Z (7 months ago)
• Last Synced: 2024-10-14T20:58:29.889Z (30 days ago)
• Language: Python
• Homepage:
• Size: 378 KB
• Stars: 117
• Watchers: 3
• Forks: 9
• Open Issues: 13
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# duct.py [![Actions Status](https://github.com/oconnor663/duct.py/workflows/tests/badge.svg)](https://github.com/oconnor663/duct.py/actions) [![Coverage Status](https://coveralls.io/repos/oconnor663/duct.py/badge.svg?branch=master&service=github)](https://coveralls.io/github/oconnor663/duct.py?branch=master) [![PyPI version](https://badge.fury.io/py/duct.svg)](https://pypi.python.org/pypi/duct) [![Documentation Status](https://readthedocs.org/projects/ductpy/badge/?version=latest)](https://ductpy.readthedocs.io/en/latest/?badge=latest)

Duct is a library for running child processes. Duct makes it easy to

build pipelines and redirect IO like a shell. At the same time, Duct

helps you write correct, portable code: whitespace is never significant,

errors from child processes get reported by default, and a variety of

[gotchas, bugs, and platform

inconsistencies](https://github.com/oconnor663/duct.py/blob/master/gotchas.md)

are handled for you the Right Way™.

- [Documentation](https://ductpy.readthedocs.io)

- [PyPI package](https://pypi.python.org/pypi/duct)

- [the same library, in Rust](https://github.com/oconnor663/duct.rs)

Examples

--------

Run a command without capturing any output. Here "hi" is printed directly to

the terminal:

```python

>>> from duct import cmd

>>> cmd("echo", "hi").run()

hi

Output(status=0, stdout=None, stderr=None)

```

Capture the standard output of a command. Here "hi" is returned as a string:

```python

>>> cmd("echo", "hi").read()

'hi'

```

Capture the standard output of a pipeline:

```python

>>> cmd("echo", "hi").pipe(cmd("sed", "s/i/o/")).read()

'ho'

```

Merge standard error into standard output and read both incrementally:

```python

>>> big_cmd = cmd("bash", "-c", "echo out && echo err 1>&2")

>>> reader = big_cmd.stderr_to_stdout().reader()

>>> with reader:

...     reader.readlines()

[b'out\n', b'err\n']

```

Children that exit with a non-zero status raise an exception by default:

```python

>>> cmd("false").run()

Traceback (most recent call last):

...

duct.StatusError: Expression cmd('false') returned non-zero exit status: Output(status=1, stdout=None, stderr=None)

>>> cmd("false").unchecked().run()

Output(status=1, stdout=None, stderr=None)

```