The default value of __len__ is 0, not 1:
>>> from unittest.mock import MagicMock
>>> mock = MagicMock()
>>> len(mock)
0
Reported by Alex on docs@p.o.
Remove the remaining VMSError reference. VMS support is gone.
This restores details lost in revision 097f4fda61a4 (since Python 3.3,
related to the new OSError subclasses). Further additions:
* Markup for attributes and constructor signature
* Explain "winerror" and "filename2"
* Extend test to check for filename2 defaulting to None
* Clarify that the constructor can return a subclass
I have intentionally left out any details of allowing more than five
arguments, or how the "args" attribute is set for four or more arguments.
These details seem to be dependent on the Python version and platform.
timeout when interrupted by a signal, except if the signal handler raises an
exception. This change is part of the PEP 475.
The asyncore and selectors module doesn't catch the InterruptedError exception
anymore when calling select.select(), since this function should not raise
InterruptedError anymore.
now register both filenames in the exception on failure.
This required adding new C API functions allowing OSError exceptions
to reference two filenames instead of one.
Forgot to raise ModuleNotFoundError when None is found in sys.modules.
This led to introducing the C function PyErr_SetImportErrorSubclass()
to make setting ModuleNotFoundError easier.
Also updated the reference docs to mention ModuleNotFoundError
appropriately. Updated the docs for ModuleNotFoundError to mention the
None in sys.modules case.
Lastly, it was noticed that PyErr_SetImportError() was not setting an
exception when returning None in one case. That issue is now fixed.
ImportError.
The exception is raised by import when a module could not be found.
Technically this is defined as no viable loader could be found for the
specified module. This includes ``from ... import`` statements so that
the module usage is consistent for all situations where import
couldn't find what was requested.
This should allow for the common idiom of::
try:
import something
except ImportError:
pass
to be updated to using ModuleNotFoundError and not accidentally mask
ImportError messages that should propagate (e.g. issues with a
loader).
This work was driven by the fact that the ``from ... import``
statement needed to be able to tell the difference between an
ImportError that simply couldn't find a module (and thus silence the
exception so that ceval can raise it) and an ImportError that
represented an actual problem.
- not allowed when implicitly re-raised the current exception
- last exception raised is always displayed last
- attempt to make it clearer when/if cause and context are shown
Pass the original filename argument to OSError constructor, instead of trying
to encode it to or decode it from the filesystem encoding. This change avoids
an additionnal UnicodeDecodeError on Windows if the filename cannot be decoded
from the filesystem encoding (ANSI code page).
Currently import does not use these attributes as they are planned
for use by importlib (which will be another commit).
Thanks to Filip Gruszczyński for the initial patch and Brian Curtin
for refining it.