In mathematics, the dot product or scalar product is an algebraic operation that takes two equal-length sequences of numbers (usually coordinate vectors) and returns a single number.
For example:
import numpy as np
#define a vector of 1 and 2
a = np.array([1,2])
#define a vector of 2 and 1
b = np.array([2,1])
dot = 0
for e, f in zip(a,b):
dot += e*f
#prints 4
print(dot)
#also prints 4
print(np.sum(a*b))
#also prints 4
print(np.dot(a,b))
#also prints 4
print(a.dot(b))
#also prints 4
print(b.dot(a))
**This article is written for Python 3.6