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Diffstat (limited to 'Doc/library/argparse.rst')
| -rw-r--r-- | Doc/library/argparse.rst | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst index 73f94808b6..24060f06bc 100644 --- a/Doc/library/argparse.rst +++ b/Doc/library/argparse.rst @@ -135,7 +135,7 @@ ArgumentParser objects formatter_class=argparse.HelpFormatter, \ prefix_chars='-', fromfile_prefix_chars=None, \ argument_default=None, conflict_handler='error', \ - add_help=True) + add_help=True, allow_abbrev=True) Create a new :class:`ArgumentParser` object. All parameters should be passed as keyword arguments. Each parameter has its own more detailed description @@ -169,6 +169,12 @@ ArgumentParser objects * add_help_ - Add a -h/--help option to the parser (default: ``True``) + * allow_abbrev_ - Allows long options to be abbreviated if the + abbreviation is unambiguous. (default: ``True``) + + .. versionchanged:: 3.5 + *allow_abbrev* parameter was added. + The following sections describe how each of these are used. @@ -518,6 +524,26 @@ calls, we supply ``argument_default=SUPPRESS``:: >>> parser.parse_args([]) Namespace() +.. _allow_abbrev: + +allow_abbrev +^^^^^^^^^^^^ + +Normally, when you pass an argument list to the +:meth:`~ArgumentParser.parse_args` method of a :class:`ArgumentParser`, +it :ref:`recognizes abbreviations <prefix-matching>` of long options. + +This feature can be disabled by setting ``allow_abbrev`` to ``False``:: + + >>> parser = argparse.ArgumentParser(prog='PROG', allow_abbrev=False) + >>> parser.add_argument('--foobar', action='store_true') + >>> parser.add_argument('--foonley', action='store_false') + >>> parser.parse_args(['--foon']) + usage: PROG [-h] [--foobar] [--foonley] + PROG: error: unrecognized arguments: --foon + +.. versionadded:: 3.5 + conflict_handler ^^^^^^^^^^^^^^^^ @@ -1410,9 +1436,9 @@ argument:: Argument abbreviations (prefix matching) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -The :meth:`~ArgumentParser.parse_args` method allows long options to be -abbreviated to a prefix, if the abbreviation is unambiguous (the prefix matches -a unique option):: +The :meth:`~ArgumentParser.parse_args` method :ref:`by default <allow_abbrev>` +allows long options to be abbreviated to a prefix, if the abbreviation is +unambiguous (the prefix matches a unique option):: >>> parser = argparse.ArgumentParser(prog='PROG') >>> parser.add_argument('-bacon') @@ -1426,6 +1452,7 @@ a unique option):: PROG: error: ambiguous option: -ba could match -badger, -bacon An error is produced for arguments that could produce more than one options. +This feature can be disabled by setting :ref:`allow_abbrev` to ``False``. Beyond ``sys.argv`` @@ -1910,7 +1937,7 @@ Customizing file parsing Arguments that are read from a file (see the *fromfile_prefix_chars* keyword argument to the :class:`ArgumentParser` constructor) are read one - argument per line. :meth:`convert_arg_line_to_args` can be overriden for + argument per line. :meth:`convert_arg_line_to_args` can be overridden for fancier reading. This method takes a single argument *arg_line* which is a string read from |