Welcome to jaraco.context documentation!

For Enterprise

Professional support for jaraco.context is available as part of the Tidelift Subscription. Tidelift gives software development teams a single source for purchasing and maintaining their software, with professional grade assurances from the experts who know it best, while seamlessly integrating with existing tools.

Learn more Request a Demo

class jaraco.context.ExceptionTrap(exceptions=(Exception,))

Bases: object

A context manager that will catch certain exceptions and provide an indication they occurred.

>>> with ExceptionTrap() as trap:
...     raise Exception()
>>> bool(trap)
True

>>> with ExceptionTrap() as trap:
...     pass
>>> bool(trap)
False

>>> with ExceptionTrap(ValueError) as trap:
...     raise ValueError("1 + 1 is not 3")
>>> bool(trap)
True
>>> trap.value
ValueError('1 + 1 is not 3')
>>> trap.tb
<traceback object at ...>

>>> with ExceptionTrap(ValueError) as trap:
...     raise Exception()
Traceback (most recent call last):
...
Exception

>>> bool(trap)
False
exc_info = (None, None, None)
passes(func)

Wrap func and replace the result with the truth value of the trap (True if no exception).

First, give the decorator an alias to support Python 3.8 Syntax.

>>> passes = ExceptionTrap(ValueError).passes

Now decorate a function that always fails.

>>> @passes
... def fail():
...     raise ValueError('failed')

>>> fail()
False
raises(func, *, _test=bool)

Wrap func and replace the result with the truth value of the trap (True if an exception occurred).

First, give the decorator an alias to support Python 3.8 Syntax.

>>> raises = ExceptionTrap(ValueError).raises

Now decorate a function that always fails.

>>> @raises
... def fail():
...     raise ValueError('failed')
>>> fail()
True
property tb
property type
property value
class jaraco.context.on_interrupt(action='error', /, code=1)

Bases: ContextDecorator

Replace a KeyboardInterrupt with SystemExit(1).

Useful in conjunction with console entry point functions.

>>> def do_interrupt():
...     raise KeyboardInterrupt()
>>> on_interrupt('error')(do_interrupt)()
Traceback (most recent call last):
...
SystemExit: 1
>>> on_interrupt('error', code=255)(do_interrupt)()
Traceback (most recent call last):
...
SystemExit: 255
>>> on_interrupt('suppress')(do_interrupt)()
>>> with __import__('pytest').raises(KeyboardInterrupt):
...     on_interrupt('ignore')(do_interrupt)()
jaraco.context.pushd(dir: str | PathLike) → Iterator[str | PathLike]
>>> tmp_path = getfixture('tmp_path')
>>> with pushd(tmp_path):
...     assert os.getcwd() == os.fspath(tmp_path)
>>> assert os.getcwd() != os.fspath(tmp_path)
jaraco.context.remove_readonly(func, path, exc_info)

Add support for removing read-only files on Windows.

jaraco.context.repo_context(url, branch: str | None = None, quiet: bool = True, dest_ctx=robust_temp_dir)

Check out the repo indicated by url.

If dest_ctx is supplied, it should be a context manager to yield the target directory for the check out.

>>> repo = repo_context('https://github.com/jaraco/jaraco.context')
>>> with repo as dest:
...     listing = os.listdir(dest)
>>> 'README.rst' in listing
True
jaraco.context.robust_remover()
jaraco.context.robust_temp_dir(*, remover=<function rmtree>)

Create a temporary directory context. Pass a custom remover to override the removal behavior.

>>> import pathlib
>>> with temp_dir() as the_dir:
...     assert os.path.isdir(the_dir)
>>> assert not os.path.exists(the_dir)
jaraco.context.strip_first_component(member: TarInfo, path) → TarInfo
class jaraco.context.suppress(*exceptions)

Bases: suppress, ContextDecorator

A version of contextlib.suppress with decorator support.

>>> @suppress(KeyError)
... def key_error():
...     {}['']
>>> key_error()
jaraco.context.tarball(url, target_dir: str | PathLike | None = None) → Iterator[str | PathLike]

Get a URL to a tarball, download, extract, yield, then clean up.

Assumes everything in the tarball is prefixed with a common directory. That common path is stripped and the contents are extracted to target_dir, similar to passing -C {target} --strip-components 1 to the tar command.

Uses the streaming protocol to extract the contents from a stream in a single pass without loading the whole file into memory.

>>> import urllib.request
>>> url = getfixture('tarfile_served')
>>> target = getfixture('tmp_path') / 'out'
>>> tb = tarball(url, target_dir=target)
>>> import pathlib
>>> with tb as extracted:
...     contents = pathlib.Path(extracted, 'contents.txt').read_text(encoding='utf-8')
>>> assert not os.path.exists(extracted)

If the target is not specified, contents are extracted to a directory relative to the current working directory named after the name of the file as extracted from the URL.

>>> target = getfixture('tmp_path')
>>> with pushd(target), tarball(url):
...     target.joinpath('served').is_dir()
True
jaraco.context.tarball_cwd(*args, **kwargs)

A tarball context with the current working directory pointing to the contents.

jaraco.context.temp_dir(remover=shutil.rmtree)

Create a temporary directory context. Pass a custom remover to override the removal behavior.

>>> import pathlib
>>> with temp_dir() as the_dir:
...     assert os.path.isdir(the_dir)
>>> assert not os.path.exists(the_dir)

Indices and tables