numpy random ndarray code example

Example 1: random array numpy

>>> np.random.rand(3,2)
array([[ 0.14022471,  0.96360618],  
       [ 0.37601032,  0.25528411],  
       [ 0.49313049,  0.94909878]]) 

>>> np.random.random_integers(low=0, high=9, size=(3,2))
array([[2, 3],
       [2, 3],
       [6, 3]])

Example 2: np.random.rand()

# train test split
df = pd.read_csv('file_location')
mask = np.random.rand(len(df)) < 0.8
train  = df[mask]
test = df[~mask]