def _check_scale(scale):
 if (np.isscalar(scale) and (scale <= 0)):
  raise ValueError(('scale must be positive, not %s' % scale))

def _check_scale ( scale ) : if ( np . isscalar ( scale ) and ( scale <= 0 ) ) : raise ValueError ( ( 'scale must be positive, not %s' % scale ) )
ensure valid scale value is passed .