import numpy as np
n = 2
X = np.empty(shape=[0, n])
for i in range(5):
for j in range(2):
X = np.append(X, [[i, j]], axis=0)
print X
a = []
for x in y:
a.append(x)
a = np.array(a)
# Create an empty array with 2 elements
np.empty(2)
array([ 3.14, 42. ]) # may vary