From 863392c96fb2fe8f5e4593e9481778f88b260cce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Ma=C5=9Blanka?= <piotr.maslanka@henrietta.com.pl>
Date: Tue, 25 May 2021 19:10:23 +0200
Subject: [PATCH] added reraise_as
---
CHANGELOG.md | 2 +
docs/coding/functions.rst | 3 +
satella/__init__.py | 2 +-
satella/coding/__init__.py | 4 +-
satella/coding/decorators/arguments.py | 3 +-
satella/coding/expect_exception.py | 2 +-
satella/coding/predicates.py | 2 +-
satella/coding/recast_exceptions.py | 84 ++++++++++++++++++++++++--
tests/test_coding/test_rethrow.py | 20 +++++-
9 files changed, 111 insertions(+), 11 deletions(-)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a347bad..21fd24ff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1 +1,3 @@
# v2.16.5
+
+* added `reraise_as`
diff --git a/docs/coding/functions.rst b/docs/coding/functions.rst
index c68e74ee..828ab5fd 100644
--- a/docs/coding/functions.rst
+++ b/docs/coding/functions.rst
@@ -39,6 +39,9 @@ Functions and decorators
.. autoclass:: satella.coding.rethrow_as
:members:
+.. autoclass:: satella.coding.reraise_as
+ :members:
+
.. autofunction:: satella.coding.catch_exception
.. autofunction:: satella.coding.raises_exception
diff --git a/satella/__init__.py b/satella/__init__.py
index f56af103..d0d3958f 100644
--- a/satella/__init__.py
+++ b/satella/__init__.py
@@ -1 +1 @@
-__version__ = '2.16.5a1'
+__version__ = '2.16.5a2'
diff --git a/satella/coding/__init__.py b/satella/coding/__init__.py
index fa8cfbfa..d30cbf43 100644
--- a/satella/coding/__init__.py
+++ b/satella/coding/__init__.py
@@ -18,11 +18,11 @@ from .misc import update_if_not_none, update_key_if_none, update_attr_if_none, q
enum_value
from .overloading import overload, class_or_instancemethod
from .recast_exceptions import rethrow_as, silence_excs, catch_exception, log_exceptions, \
- raises_exception
+ raises_exception, reraise_as
from .expect_exception import expect_exception
__all__ = [
- 'Closeable', 'contains', 'enum_value',
+ 'Closeable', 'contains', 'enum_value', 'reraise_as',
'expect_exception',
'overload', 'class_or_instancemethod',
'update_if_not_none', 'DocsFromParent', 'update_key_if_none', 'queue_iterator',
diff --git a/satella/coding/decorators/arguments.py b/satella/coding/decorators/arguments.py
index dfda9fdf..4591b4fa 100644
--- a/satella/coding/decorators/arguments.py
+++ b/satella/coding/decorators/arguments.py
@@ -80,7 +80,8 @@ def execute_before(callable_: tp.Callable) -> tp.Callable:
>>> def do_things():
>>> print('Things are done')
- Then the following will print 'Things are done'
+ Then the following will print :code:`Things are done`:
+
>>> @do_things
>>> def nothing():
>>> ...
diff --git a/satella/coding/expect_exception.py b/satella/coding/expect_exception.py
index 06b2cc65..f22187c7 100644
--- a/satella/coding/expect_exception.py
+++ b/satella/coding/expect_exception.py
@@ -4,7 +4,7 @@ import typing as tp
class expect_exception:
"""
- A decorator to use as following:
+ A context manager to use as following:
>>> a = {'test': 2}
>>> with expect_exception(KeyError, ValueError, 'KeyError not raised'):
diff --git a/satella/coding/predicates.py b/satella/coding/predicates.py
index 8f828e00..80acbd48 100644
--- a/satella/coding/predicates.py
+++ b/satella/coding/predicates.py
@@ -4,7 +4,7 @@ import typing as tp
from satella.coding.typing import Predicate
from satella.configuration.schema import Descriptor
-__all__ = ['x', 'build_structure']
+__all__ = ['x', 'build_structure', 'PredicateClass']
import warnings
diff --git a/satella/coding/recast_exceptions.py b/satella/coding/recast_exceptions.py
index 437954af..e57d7a38 100644
--- a/satella/coding/recast_exceptions.py
+++ b/satella/coding/recast_exceptions.py
@@ -4,7 +4,8 @@ import threading
import typing as tp
from .decorators.decorators import wraps
-from .typing import ExceptionClassType, T, NoArgCallable
+from .typing import ExceptionClassType, T, NoArgCallable, ExceptionList
+
def silence_excs(*exc_types: ExceptionClassType, returns=None,
@@ -129,6 +130,73 @@ class log_exceptions:
return inner
+# noinspection PyPep8Naming
+class reraise_as:
+ """
+ Transform some exceptions into others.
+
+ Either a decorator or a context manager
+
+ New exception will be created by calling exception to transform to with
+ repr of current one.
+
+ You can also provide just two exceptions, eg.
+
+ >>> reraise_as(NameError, ValueError, 'a value error!')
+
+ You can also provide a catch-all:
+
+ >>> reraise_as((NameError, ValueError), OSError, 'an OS error!')
+
+ New exception will be raised from the one caught!
+
+ .. note:: This checks if exception matches directly via :code:`isinstance`, so defining
+ your own subclassing hierarchy by :code:`__isinstance__` or :code:`__issubclass__`
+ will work here.
+
+ This is meant as an improvement of :class:`~satella.coding.rethrow_as`
+
+ :param source_exc: source exception or a tuple of exceptions to catch
+ :param target_exc: target exception to throw. If given a None, the exception will
+ be silently swallowed.
+ :param args: arguments to constructor of target exception
+ :param kwargs: keyword arguments to constructor of target exception
+ """
+ __slots__ = 'source', 'target_exc', 'args', 'kwargs'
+
+ def __init__(self, source_exc: ExceptionList,
+ target_exc: tp.Optional[ExceptionClassType], *args, **kwargs):
+ self.source = source_exc
+ self.target_exc = target_exc
+ self.args = args
+ self.kwargs = kwargs
+
+ def __call__(self, fun: tp.Callable) -> tp.Callable:
+ @wraps(fun)
+ def inner(*args, **kwargs):
+ try:
+ return fun(*args, **kwargs)
+ except Exception as e:
+ if isinstance(e, self.source):
+ if self.target_exc is not None:
+ raise self.target_exc(*self.args, **self.kwargs) from e
+ else:
+ raise
+
+ return inner
+
+ def __enter__(self):
+ return self
+
+ def __exit__(self, exc_type, exc_val, exc_tb):
+ if exc_val is not None:
+ if isinstance(exc_val, self.source):
+ if self.target_exc is None:
+ return True
+ raise self.target_exc(*self.args, **self.kwargs) from exc_val
+ return False
+
+
# noinspection PyPep8Naming
class rethrow_as:
"""
@@ -139,6 +207,10 @@ class rethrow_as:
New exception will be created by calling exception to transform to with
repr of current one.
+ .. note:: This checks if exception matches directly via :code:`isinstance`, so defining
+ your own subclassing hierarchy by :code:`__isinstance__` or :code:`__issubclass__`
+ will work here.
+
You can also provide just two exceptions, eg.
>>> rethrow_as(NameError, ValueError)
@@ -152,6 +224,10 @@ class rethrow_as:
Pass tuples of (exception to catch - exception to transform to).
+ .. warning:: Try to use :class:`~satella.coding.reraise_as` instead.
+ However, during to richer set of switches and capability to return a value
+ this is not deprecated.
+
:param exception_preprocessor: other callable/1 to use instead of repr.
Should return a str, a text description of the exception
:param returns: what value should the function return if this is used as a decorator
@@ -159,10 +235,10 @@ class rethrow_as:
is used as as decorator
:raises ValueError: you specify both returns and returns_factory
"""
- __slots__ = ('mapping', 'exception_preprocessor', 'returns', '__exception_remapped',
- 'returns_factory')
+ __slots__ = 'mapping', 'exception_preprocessor', 'returns', '__exception_remapped', \
+ 'returns_factory'
- def __init__(self, *pairs: tp.Union[ExceptionClassType, tp.Tuple[ExceptionClassType, ...]],
+ def __init__(self, *pairs: ExceptionList,
exception_preprocessor: tp.Optional[tp.Callable[[Exception], str]] = repr,
returns=None,
returns_factory: tp.Optional[NoArgCallable[tp.Any]] = None):
diff --git a/tests/test_coding/test_rethrow.py b/tests/test_coding/test_rethrow.py
index d3ccc75a..85bb07c7 100644
--- a/tests/test_coding/test_rethrow.py
+++ b/tests/test_coding/test_rethrow.py
@@ -1,7 +1,8 @@
import logging
import unittest
-from satella.coding import rethrow_as, silence_excs, catch_exception, log_exceptions, raises_exception
+from satella.coding import rethrow_as, silence_excs, catch_exception, log_exceptions, \
+ raises_exception, reraise_as
logger = logging.getLogger(__name__)
@@ -135,6 +136,23 @@ class TestStuff(unittest.TestCase):
self.assertRaises(NameError, lol)
+ def test_reraise(self):
+ try:
+ with reraise_as(ValueError, NameError):
+ raise ValueError()
+ except NameError:
+ return
+
+ self.fail()
+
+ def test_reraise_silencer(self):
+
+ @reraise_as(ValueError, None)
+ def lol():
+ raise ValueError()
+
+ lol()
+
def test_issue_10(self):
class WTFException1(Exception): pass
--
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