bpo-34067: Include a more easily understood example for nullcontext (GH-8158)
Include a more easily understood example for nullcontext
diff --git a/Doc/library/contextlib.rst b/Doc/library/contextlib.rst
index 54d3a8e..0b1f4f7 100644
--- a/Doc/library/contextlib.rst
+++ b/Doc/library/contextlib.rst
@@ -152,10 +152,22 @@
.. function:: nullcontext(enter_result=None)
- Return a context manager that returns enter_result from ``__enter__``, but
+ Return a context manager that returns *enter_result* from ``__enter__``, but
otherwise does nothing. It is intended to be used as a stand-in for an
optional context manager, for example::
+ def myfunction(arg, ignore_exceptions=False):
+ if ignore_exceptions:
+ # Use suppress to ignore all exceptions.
+ cm = contextlib.suppress(Exception)
+ else:
+ # Do not ignore any exceptions, cm has no effect.
+ cm = contextlib.nullcontext()
+ with cm:
+ # Do something
+
+ An example using *enter_result*::
+
def process_file(file_or_path):
if isinstance(file_or_path, str):
# If string, open file