Answers for "np.vstack()"

numpy stack arrays vertically

import numpy as np
# ensure same shape of arrays to be stacked.
a = np.arange(10).reshape(2,-1)
b = np.repeat(1, 10).reshape(2,-1)
# use vstack() to stack by row.
out = np.vstack((a,b))
## print output
print(out)
# a
# b

vstack numpy

>>> a = np.array([[1], [2], [3]])
>>> b = np.array([[4], [5], [6]])
>>> np.vstack((a,b))
array([[1],
       [2],
       [3],
       [4],
       [5],
       [6]])