Merge #14399: corrected news item

1 files changed, 25 insertions, 6 deletions

diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 0123b5cbac..50ccb3135f 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -362,16 +362,16 @@ formatter_class
 ^^^^^^^^^^^^^^^
 
 :class:`ArgumentParser` objects allow the help formatting to be customized by
-specifying an alternate formatting class.  Currently, there are three such
+specifying an alternate formatting class.  Currently, there are four such
 classes:
 
 .. class:: RawDescriptionHelpFormatter
            RawTextHelpFormatter
            ArgumentDefaultsHelpFormatter
+           MetavarTypeHelpFormatter
 
-The first two allow more control over how textual descriptions are displayed,
-while the last automatically adds information about argument default values.
-
+:class:`RawDescriptionHelpFormatter` and :class:`RawTextHelpFormatter` give
+more control over how textual descriptions are displayed.
 By default, :class:`ArgumentParser` objects line-wrap the description_ and
 epilog_ texts in command-line help messages::
 
@@ -424,8 +424,8 @@ should not be line-wrapped::
 :class:`RawTextHelpFormatter` maintains whitespace for all sorts of help text,
 including argument descriptions.
 
-The other formatter class available, :class:`ArgumentDefaultsHelpFormatter`,
-will add information about the default value of each of the arguments::
+:class:`ArgumentDefaultsHelpFormatter` automatically adds information about
+default values to each of the argument help messages::
 
    >>> parser = argparse.ArgumentParser(
    ...     prog='PROG',
@@ -442,6 +442,25 @@ will add information about the default value of each of the arguments::
     -h, --help  show this help message and exit
     --foo FOO   FOO! (default: 42)
 
+:class:`MetavarTypeHelpFormatter` uses the name of the type_ argument for each
+argument as the display name for its values (rather than using the dest_
+as the regular formatter does)::
+
+   >>> parser = argparse.ArgumentParser(
+   ...     prog='PROG',
+   ...     formatter_class=argparse.MetavarTypeHelpFormatter)
+   >>> parser.add_argument('--foo', type=int)
+   >>> parser.add_argument('bar', type=float)
+   >>> parser.print_help()
+   usage: PROG [-h] [--foo int] float
+
+   positional arguments:
+     float
+
+   optional arguments:
+     -h, --help  show this help message and exit
+     --foo int
+
 
 conflict_handler
 ^^^^^^^^^^^^^^^^