Syntax:
np.vstack((a, b, ...))
Example:
import numpy as np
a = np.array([1, 2, 3])
b = np.array([4, 5, 6])
stacked = np.vstack((a, b))
[[1 2 3]
[4 5 6]]
import numpy as np
x = np.array([7, 8, 9])
y = np.array([10, 11, 12])
result = np.vstack((x, y))
print(result)
[[ 7 8 9]
[10 11 12]]