Duplicate values from array for new array with python [duplicate]

My input array is: [ 37. -18. 27.]

Now I wanted to create such array (every value four times): [ 37. 37. 37. 37. -18. -18. -18. -18. 27. 27. 27. 27.]

import numpy as np
abc = (37.0, -18.0, 27.0)
xyz = np.array(abc)
for i in range(len(xyz)):
    four = (xyz[i], xyz[i], xyz[i], xyz[i])

Now, the output isn't the right one. I want to have an one-dimensional array as a result. Does somebody have an idea?