Answer 1

#Numpy has append and accept two arguments.
#https://docs.scipy.org/doc/numpy-1.13.0/reference/generated/numpy.append.html
# Example:
import numpy as np

test = np.array([])
test = np.append(int,range(10))
print(test)
# Or

test_1 = np.array([])
test_1 = np.append(np.random.randint(10,size=5),"")
print(test_1)