a = np.arange(12).reshape(4,3)
a

b = np.array([True, False, True, False])
a[b,:]

a[b]

b = np.array([True, False, True])
a[b,:]

b = [True, False, True, False]
a[b], a[b,:]

b = [0, 2]
a[b,:]

a = np.arange(16).reshape((2,2,4))
a

b = np.array([[True, False], [True, False]])
a[b,:]

a[[0,1], [0, 0], :]

a[b.nonzero()]

a = np.array([[1,2],[3,4]])
b = np.array([[5,6],[7,8]])
a_ = a[..., np.newaxis]
b_ = b[..., np.newaxis]
c = np.concatenate((a_, b_), 2)
c

c = np.array([a, b])
c

np.rollaxis(c,0,3)