argparse 2.0.1

• Improved passing of arguments to Python from R. In particular should fix bug in using add_help argument in ArgumentParser. Thanks George Chlipala for bug report.
• Removes getopt as a dependency.

argparse 2.0.0

• Now uses R6 classes instead of proto classes (#25).
  The typical user shouldn’t need to change any argparse code but I did make private the previously public python_code element of the object returned by ArgumentParser().
• Parsers now support add_subparsers (#14). Suggestion of Zebulun Arendsee.
• Parsers now support add_argument_group (#26).
  Suggestion of Dario Beraldi.
• Parsers now support add_mutually_exclusive_group (#23).
  Suggestion of Vince Reuter.

argparse 1.1.1

• Better support for machines only running Python 2.7.
  
• DESCRIPTION makes explicit that it requires version 1.0.0 of proto dependency.
  Thanks Christophe Poulet for bug report.

argparse 1.1.0

• Better support for Unicode arguments/options. Thanks Erick Rocha Fonseca for bug report.
• Fix bug when setting type='integer' in add_argument. Thanks Dominik Mueller for bug report and suggested solution.
• The package proto has been moved from Depends to Imports in DESCRIPTION. We now use jsonlite package instead of rjson to parse JSON.
• Better error message when accidentally trying to define a positional argument in ArgumentParser() Suggestion of Alex Reinhart.
• Other error message output when an parsing error is detected have been tweaked slightly.

argparse 1.0.7

• Now supports showing program’s version with action='version'. Suggestion of Dario Beraldi.

argparse 1.0.6

• Fix bug when setting required=FALSE in add_argument. Thanks Claire D. McWhite for bug report.

argparse 1.0.4

• You can now pass in a character vector to the metavar argument of add_argument. Thanks Paul Newell for bug report and a patch.

argparse 1.0.3

• add_argument now throws a warning recommending using action “store_true” or “store_false” if type set to “logical” and action set to “store”. Suggestion of Martí Duran Ferrer
• You can now explicitly set a NULL default in add_argument.
  Previously one could only implicitly set a NULL default by not setting any default at all. Suggestion of Hyunsoo Kim.

argparse 1.0.2

• Fixes parsing bug when using a very large argument list. Thanks Taylor Pospisil for bug report.
• Parse error usage message now prints to standard error. User requested help message quit status is now zero.
  Thanks to PlasmaBinturong for report/request.
• If Python script fails with error pass on error message to user. Thanks to Martí Duran Ferrer for report/request.

argparse 1.0.1

• Fix minor bug when running package tests on machines with both old and new versions of Python. Thanks Prof. Brian Ripley for bug report.

argparse 1.0.0

• Some support for choices argument in parser$add_argument. Thanks Christopher Small for report/request.

• Some support for formatter_class argument in ArgumentParser. Thanks Costas Bouyioukos for report/request.

• Package now looks for Python binaries with findpython::find_python_cmd which is a little bit more robust than the previous argparse::find_python_cmd.

• If interactive() == TRUE then parse_args will no longer quit(status=1) after printing a help message but will instead throw an error. argparse will continue to quit(status=1) after printing a help message for non-interactive Rscripts.

argparse 0.5.3

• Fix bug in parser$add_argument for case when we specify a default vector instead of scalar. Thanks Martin Diehl for bug report.

• find_python_cmd will now also look for a python2.7 binary.

• Website moved to https://github.com/trevorld/argparse