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Diffstat (limited to 'Doc/library/argparse.rst')
| -rw-r--r-- | Doc/library/argparse.rst | 35 |
1 files changed, 27 insertions, 8 deletions
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst index e4add74..17a56dd 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:: @@ -395,7 +395,7 @@ epilog_ texts in command-line help messages:: likewise for this epilog whose whitespace will be cleaned up and whose words will be wrapped across a couple lines -Passing :class:`~argparse.RawDescriptionHelpFormatter` as ``formatter_class=`` +Passing :class:`RawDescriptionHelpFormatter` as ``formatter_class=`` indicates that description_ and epilog_ are already correctly formatted and should not be line-wrapped:: @@ -421,11 +421,11 @@ should not be line-wrapped:: optional arguments: -h, --help show this help message and exit -:class:`RawTextHelpFormatter` maintains whitespace for all sorts of help text +: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 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 ^^^^^^^^^^^^^^^^ |