.. _fwflag_print_numgroups:
===================
--print_numgroups
===================
Switch
======

--print_numgroups

Description
===========

Prints the number of groups available for each outcome field.

Argument and Default Value
==========================

No argument. Boolean switch, default: ``False``.

Details
=======

**Known issue — crashes when used on its own.** The handler is:

.. code-block:: python

    if args.printnumgroups:
        pprint(args)
        if not oa: oa = OA()
        if not fg: fg = FG()
        pprint(('number of groups per outcome:', og.numGroupsPerOutcome(fg, args.printcsv)))

It initializes ``oa``/``fg`` if missing, but never initializes ``og`` (the ``OutcomeGetter``) — yet it's ``og.numGroupsPerOutcome(...)`` that's called. Verified: ``--print_numgroups`` fails with ``AttributeError: 'NoneType' object has no attribute 'numGroupsPerOutcome'`` both on its own and combined with :doc:`fwflag_correlate` (which only initializes ``oa``/``fg``, not ``og``, either). No working combination was found; as of this writing there is no way to run this switch successfully.

Separately, note ``args.printcsv`` (i.e. :doc:`fwflag_print_csv`'s value) is passed in as ``numGroupsPerOutcome``'s ``outputfile`` argument, but that function never uses its ``outputfile`` parameter — output always goes to stdout via ``pprint()`` regardless of what (if anything) you pass to ``--print_csv``.

Other Switches
==============

Required Switches:

* None (flag currently cannot complete successfully — see Known issue above)

Example Commands
================

Not usable as of this writing — see Known issue above.