gistfile1.py

def _pofile_or_mofile(f, type, **kwargs):
    # ... snip
    
    default_klass = type == 'pofile' and POFile or MOFile
    klass = kwargs.get('klass', default_klass) 

    parser = kls(
        f,
        encoding=enc,
        check_for_duplicates=kwargs.get('check_for_duplicates', False),
        klass=klass,
    )
    # ... snip

class _POFileParser(object):
    def __init__(self, pofile, *args, **kwargs):
        # ... snip
        klass = kwargs.get('klass', POFile)
        # ... snip