coefficient of correlation

correlation.py

#!/bin/env python3
import math

def mul(x, y):
    xy = []
    for a,b in zip(x,y):
        xy.append(a*b)
    return xy

def total(arr):
    total = 0
    for e in arr:
        total+=e;
    return total

def mean(total, n):
    return total/n


def squre(arr):
    sqr = []
    for e in arr:
        sqr.append(e**2)
    return sqr

def corre(n, total_xy, total_x_total_y, total_sqr_x, sqr_total_x, total_sqr_y, sqr_total_y):
    denom = (n*total_xy)-(total_x_total_y)
    nome = math.sqrt((n*total_sqr_x)-sqr_total_x) * math.sqrt((n*total_sqr_y)-sqr_total_y)
    return denom/nome

def main():
    n = int(input("N: "))
    x = []; y = []
    print("-- x values --")
    for i in range(n):
        num = input("value: ")
        try:
            x.append(int(num))
        except:
            x.append(float(num))
    print("-- y values --")
    for i in range(n):
        num = input("value: ")
        try:
            y.append(int(num))
        except:
            y.append(float(num))

    xy = mul(x, y)
    total_x = total(x)
    total_y = total(y)
    total_xy = total(xy)
    sqr_x = squre(x)
    sqr_y = squre(y)
    total_sqr_x = total(sqr_x)
    total_sqr_y = total(sqr_y)
    print("---------------------------")
    print("total_x:", total_x)
    print("total_y:", total_y)
    print("total_xy:", total_xy)
    print("total_sqr_x:", total_sqr_x)
    print("total_sqr_y:", total_sqr_y)
    r = corre(n, total_xy, total_x * total_y, total_sqr_x, total_x * total_x, total_sqr_y, total_y * total_y)
    print("r:", r)
main()