Find in between coordinates for the given latitude and longitude from a CSV file

Question

I have a CSV file which has the latitude and longitude values for the start and the end coordinates as follows. In these the first lon and lat values are the start point then the second coordinates are the end points for one value. Then the third point is the start and the forth is the end and so on. The csv is in the following format

lat    lon
1.25   6.45
2.45   5.36
3.67   9.67
3.56   6.25

The code which I tried is:

def main(interval,azimuth,lat1,lng1,lat2,lng2):
    '''returns every coordinate pair inbetween two coordinate 
    pairs given the desired interval'''

    d = getPathLength(lat1,lng1,lat2,lng2)
    remainder, dist = math.modf((d / interval))
    counter = float(interval)
    coords = []
    coords.append([lat1,lng1])
    for distance in range(0,int(dist)):
        coord = getDestinationLatLong(lat1,lng1,azimuth,counter)
        counter = counter + float(interval)
        coords.append(coord)
    coords.append([lat2,lng2])
    return coords

if __name__ == "__main__":
#point interval in meters
interval = 10
#direction of line in degrees
#start point

lat1 =  18.750000000
lng1 =     85.416666667
#end point
lat2 =  17.650000000
lng2 =  83.250000000
azimuth = calculateBearing(lat1,lng1,lat2,lng2)
#print(azimuth)
azimuth
coords = main(interval,azimuth,lat1,lng1,lat2,lng2)
#print(coords)
coords

This code takes the coordinates manually but I need it to take values from CSV and generate the output as CSV.

Answer 1

Although I've not tested it, this script could work or at least give you an idea of what you should do in order to achieve what you want.

Hope it helps you:

import csv

# adjust as you need (the spaces between your lat/long coords in each row)
my_delimiter = '   '

#open input csv in read mode
input_csv = open('yourfile.csv', 'r', newline='')

# open output csv in append mode
output_csv = open('yourfile.csv', 'a', newline='')

coordreader = csv.reader(input_csv, delimiter=my_delimiter)

coordwriter = csv.writer(output_csv, delimiter=my_delimiter)

# iterate over each row in the input csv as a list of srings
# e.g. first line is: [1.25, 6.45]
for count, row in enumerate(coordreader):
    next(row) # skip first line (headers)
    # do this for the start coordinates
    if count % 2 == 0:
        lat1 = float(row[0])
        lng1 = float(row[1])
    # this should be your end coordinates
    if not count % 2 == 0:
        lat2 = float(row[0])
        lng2 = float(row[1])
        azimuth = calculateBearing(lat1,lng1,lat2,lng2)
        coords = main(interval,azimuth,lat1,lng1,lat2,lng2)

        # write the coords in the output csv
        coordwriter.writerow(coords)