Code pearson correlation coefficient from scratch

pearson.py

import pandas as pd
import math

lines = [line.split() for line in input.split("\n") if len(line)]

X, y = [[int(score) for score in scores] for index, (variable, _, *scores) in enumerate(lines)]

n = len(X)
sum_X, sum_y = sum(X), sum(y)
sum_Xy = sum([X[i] * y[i] for i in range(len(X))])
sum_X2 = sum([X[i] ** 2 for i in range(len(X))])
sum_y2 = sum([y[i] ** 2 for i in range(len(y))])


# use formula for calculating correlation  
# coefficient. 
corr = (n * sum_Xy - sum_X * sum_y) /\
       math.sqrt(
           (n * sum_X2 - sum_X * sum_X) * 
           (n * sum_y2 - sum_y * sum_y)
       ) 
round(corr, 3)