### Proposed new feature or change: `numpy.isin` is equivalent to `pandas.{Series,DataFrame}.isin`. Adding `numpy.ndarray.isin` would produce consistency with `pandas` and save 4 characters: ```python np.isin(x, y) # Current x.isin(y) # Proposed ``` I've posted this idea to the forum [here](https://mail.python.org/archives/list/numpy-discussion@python.org/thread/6QJJLJSM4T562YOOU3XJ774PYM6ADQVI/).