cosine_similarity.py

v1 = [0,3,4,5,6]
v2 = [4,5,6,7,8]

def dot(v1, v2):
	dot_product = sum((a * b) for a,b in zip(v1,v2))
	return dot_product

def cosine_similarity(v1, v2):
	'''
	(v1 dot v2)/||v1|| *||v2||)
	'''
	products = dot(v1,v2)
	denominator = ( (dot(v1,v1) **.5) * (dot(v2,v2) ** .5) )
	similarity = products / denominator
	return similarity

print(cosine_similarity(v1, v2))
# 0.9544074144996451