Answer to Question #271849 in Python for surendar

Question

Find latitude and longitude of first 20 countries with a population greater than or equal to the population limit given below. Use the country details from this dataset.

Your task is to find the sum of the length of all lines (in kms) that can be drawn between co-ordinates of these countries.

• Assume radius of earth: 6371 km
• Round length of each line and final result to 2 decimal points
• If co-ordinates are missing for any country use 0.000 N 0.000 E

Population limit: 277500

Note: Population limit will change at random intervals. So please make sure answer is computed for the correct population limit before submitting.

Answer 1

import json
from math import pi, sin, cos, sqrt, asin


def find_dist(latlng_1, latlng_2):
    lat1, lon1 = latlng_1[0]*pi/180, latlng_1[1]*pi/180
    lat2, lon2 = latlng_2[0]*pi/180, latlng_2[1]*pi/180
    d = 2*6371*asin(sqrt(sin((lat2-lat1)/2)**2 + cos(lat1)
                    * cos(lat2)*sin((lon2-lon1)/2)**2))
    return round(d, 2)


file = "countriesV2.json"


limit = 11750


with open(file, 'r') as f:
    contries = json.load(f)
first_20 = {}
for contry in contries:
    if contry['population'] >= limit:
        first_20[contry['alpha3Code']] = contry['latlng']
        if len(first_20) == 20:
            break


total_dist = 0
keys = list(first_20.keys())
for i in range(len(keys)-1):
    for j in range(len(keys[i+1:])):
        total_dist += find_dist(first_20[keys[i]], first_20[keys[j]])
total_dist = round(total_dist, 2)


print(total_dist)