Issue #15767: Introduce ModuleNotFoundError, a subclass of
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.
diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst
index c0c30a0..1bdcdd3 100644
--- a/Doc/c-api/exceptions.rst
+++ b/Doc/c-api/exceptions.rst
@@ -686,6 +686,8 @@
+-----------------------------------------+---------------------------------+----------+
| :c:data:`PyExc_ImportError` | :exc:`ImportError` | |
+-----------------------------------------+---------------------------------+----------+
+| :c:data:`PyExc_ModuleNotFoundError` | :exc:`ModuleNotFoundError` | |
++-----------------------------------------+---------------------------------+----------+
| :c:data:`PyExc_IndexError` | :exc:`IndexError` | |
+-----------------------------------------+---------------------------------+----------+
| :c:data:`PyExc_InterruptedError` | :exc:`InterruptedError` | |