mport pandas as p
import numpy as np
data=p.read_excel('prices.xlsx')
data2=data[1:]
def elast(p1,q1,p2,q2):
    if p2==None or q2==None:
        el=1
    else:
        el=(q2-q1)*(p1+p2)/((p2-p1)*(q1+q2))
    return el


print(map(elast,data['p_comp'][:40],data['q'][:40],data2['p_comp'][:40],data2['q'][:40]))