import sys
import csv

if len(sys.argv) < 4:
    print('Syntax: ./alt.py $COUNTRY $CITY $VARIANCE')
    sys.exit(0)

country = sys.argv[1]
city = sys.argv[2]
var = float(sys.argv[3])

data_file = open('data.csv')
data = csv.reader(data_file, delimiter=';', quotechar='"')

my_location = []

for item in data:
    if item[1] == country:
        if item[2] == city:
            my_location = item
            break

if my_location:
    print('%s, %s has an altitude of %s' % (my_location[2], my_location[1], my_location[5]))
else:
    print('Location not found in data!')
    sys.exit(0)

my_altitude = float(my_location[5])
print("\n" + 'Here are the cities that share the same altitude with you:' + "\n")

for item in data:
    if my_altitude - var < float(item[5]) and my_altitude + var > float(item[5]):
        print('%s, %s has an altitude of %s' % (item[2], item[1], item[5]))

data_file.close()