np.random.rand()*scale code example

Example 1: np.random.randn()

>>> 2.5 * np.random.randn(2, 4) + 3
array([[-4.49401501,  4.00950034, -1.81814867,  7.29718677],  #random
       [ 0.39924804,  4.68456316,  4.99394529,  4.84057254]]) #random

Example 2: np.random.randint to generate -1 +1

2 * np.random.randint(2, size=10) -1