The Cauchy-Schwarz inequality states for all vectors $$u$$ and $$v$$,

$|\langle \mathbf{u}, \mathbf{v} \rangle| \leq ||\mathbf{u}|| \ ||\mathbf{v}||$

This means that the dot product of the two vectors is less than the product of the norms of the vectors.

import numpy as np

u = np.array([3, 5, 5])
v = np.array([5, 2, 6])

np.dot(u, v) <= np.linalg.norm(u) * np.linalg.norm(v)
## True