def _bool_from_json(value, field):
 if _not_null(value, field):
  return (value.lower() in ['t', 'true', '1'])

def _bool_from_json ( value , field ) : if _not_null ( value , field ) : return ( value . lower ( ) in [ 't' , 'true' , '1' ] )
coerce value to a bool .