What is the meaning of '*' in numpy?

Question

>>> shape=(2,2)
>>> np.random.randn(*shape)
array([[-1.64633649, -0.03132273],
   [-0.92331459,  1.05325462]])

I can't find it in numpy's documentation. Any help is appreciated.

Answer 1

This is not NumPy-specific syntax; it is Python syntax. The so-called *-operator is Python syntax that does sequence unpacking in argument lists (see Unpacking Argument Lists).

The use in your example is to unpack the shape tuple into separate arguments. This is needed because numpy.random.randn takes an arbitrary number of integers as parameters, not a tuple of integers.

The code from the question is equivalent to doing:

>>> np.random.randn(2, 2)