def blackman(M, sym=True):
 if _len_guards(M):
  return np.ones(M)
 (M, needs_trunc) = _extend(M, sym)
 w = _cos_win(M, [0.42, 0.5, 0.08])
 return _truncate(w, needs_trunc)

def blackman ( M , sym = True ) : if _len_guards ( M ) : return np . ones ( M ) ( M , needs_trunc ) = _extend ( M , sym ) w = _cos_win ( M , [ 0.42 , 0.5 , 0.08 ] ) return _truncate ( w , needs_trunc )
return a blackman window .