bpo-9938: Add optional keyword argument exit_on_error to argparse.ArgumentParser (GH-15362)
Co-Authored-by: Xuanji Li <xuanji@gmail.com>
https://bugs.python.org/issue9938
Automerge-Triggered-By: @matrixise
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 368b1cf..c2cf7d3 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -142,7 +142,7 @@
formatter_class=argparse.HelpFormatter, \
prefix_chars='-', fromfile_prefix_chars=None, \
argument_default=None, conflict_handler='error', \
- add_help=True, allow_abbrev=True)
+ add_help=True, allow_abbrev=True, exit_on_error=True)
Create a new :class:`ArgumentParser` object. All parameters should be passed
as keyword arguments. Each parameter has its own more detailed description
@@ -179,6 +179,9 @@
* allow_abbrev_ - Allows long options to be abbreviated if the
abbreviation is unambiguous. (default: ``True``)
+ * exit_on_error_ - Determines whether or not ArgumentParser exits with
+ error info when an error occurs. (default: ``True``)
+
.. versionchanged:: 3.5
*allow_abbrev* parameter was added.
@@ -186,6 +189,9 @@
In previous versions, *allow_abbrev* also disabled grouping of short
flags such as ``-vv`` to mean ``-v -v``.
+ .. versionchanged:: 3.9
+ *exit_on_error* parameter was added.
+
The following sections describe how each of these are used.
@@ -647,6 +653,28 @@
+h, ++help show this help message and exit
+exit_on_error
+^^^^^^^^^^^^^
+
+Normally, when you pass an invalid argument list to the :meth:`~ArgumentParser.parse_args`
+method of an :class:`ArgumentParser`, it will exit with error info.
+
+If the user would like catch errors manually, the feature can be enable by setting
+``exit_on_error`` to ``False``::
+
+ >>> parser = argparse.ArgumentParser(exit_on_error=False)
+ >>> parser.add_argument('--integers', type=int)
+ _StoreAction(option_strings=['--integers'], dest='integers', nargs=None, const=None, default=None, type=<class 'int'>, choices=None, help=None, metavar=None)
+ >>> try:
+ ... parser.parse_args('--integers a'.split())
+ ... except argparse.ArgumentError:
+ ... print('Catching an argumentError')
+ ...
+ Catching an argumentError
+
+.. versionadded:: 3.9
+
+
The add_argument() method
-------------------------