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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
jaraco.context.infer_compression(url)

Given a URL or filename, infer the compression code for tar.

>>> infer_compression('http://foo/bar.tar.gz')
'z'
>>> infer_compression('http://foo/bar.tgz')
'z'
>>> infer_compression('file.bz')
'j'
>>> infer_compression('file.xz')
'J'
jaraco.context.null()

A null context suitable to stand in for a meaningful context.

>>> with null() as value:
...     assert value is None

This context is most useful when dealing with two or more code branches but only some need a context. Wrap the others in a null context to provide symmetry across all options.

class jaraco.context.on_interrupt(action='error', /, code=1)

Bases: ContextDecorator

Replace a KeyboardInterrupt with SystemExit(1)

>>> 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.repo_context(url, branch=None, quiet=True, dest_ctx=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.

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 tarball, extract it, yield, then clean up.

>>> 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)
jaraco.context.tarball_context(*args, **kwargs)
jaraco.context.tarball_cwd(*args, **kwargs)
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)
...     _ = pathlib.Path(the_dir).joinpath('somefile').write_text('contents', encoding='utf-8')
>>> assert not os.path.exists(the_dir)

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