havesine.py

"""
Author: Popey456963
Date:   20/05/2016 20:30
Desc:   Postcodes
"""

from math import radians, cos, sin, asin, sqrt

AVG_EARTH_RADIUS = 6371


def haversine(point1, point2):
    lat1, lng1 = point1
    lat2, lng2 = point2

    lat1, lng1, lat2, lng2 = map(radians, (lat1, lng1, lat2, lng2))

    lat = lat2 - lat1
    lng = lng2 - lng1
    d = sin(lat * 0.5) ** 2 + cos(lat1) * cos(lat2) * sin(lng * 0.5) ** 2
    h = 2 * AVG_EARTH_RADIUS * asin(sqrt(d))
    
    return h



postcode = input("<<< (Postcode) ")
postcode2 = input("<<< (Postcode 2) ")
point1 = ()
point2 = ()

with open("latlong.csv") as f:
    lines = [i.strip().split(",")[1:] for i in f.readlines()]
    lines.pop(0)
    for i in lines:
        if i[0] == postcode:
            point1 = (float(i[1]), float(i[2]))
        if i[0] == postcode:
            point2 = (float(i[1]), float(i[2]))

print(haversine(point1, point2))