formatting string and returning as geojson

[buran]

something like this (note that I'm not able to test it)

#!/usr/bin/python
import psycopg2
from config import config
import re
import geojson
import tempfile

def parse_row(row):
    # extract lat, lon
    # you may need to round the float number to
    # correct number of decimal digits

    lon = float(row[3:15])
    lat = float(row[15:27])
    return (lon, lat)

 
def get_vendorfield():
    """ Connect to the PostgreSQL database server """


    # read connection parameters
    params = config()
    # connect to the PostgreSQL server
    print('Connecting to the PostgreSQL database...')
    with psycopg2.connect(**params) as conn:
        # create a cursor
        with conn.cursor() as cur:
            try:
                cur.execute("SELECT t.id, t.\"vendorField\" FROM transactions t WHERE t.\"vendorField\" LIKE 'geo%'")
                print("Rows returned: ", cur.rowcount)
                #dashmap=(66, 3, 12, 12, 12, ) #this is used for the chunks - but the last chuck is missed because it is of unknown length
                geo_data = [parse_row(row[1]) for row in cur] # you may need to replace cur with cur.fetchall()
            except psycopg2.DatabaseError as db_error:
                print(error)
                geo_data = []

    print('Database connection closed.')
            
    if geo_data:
        multipoint_json = geojson.Multipoint(geo_data)
        with open('points.json', 'w') as outfile:
            geojson.dump(multipoint_json, outfile, indent=2)

My understanding was you want geojson.Multipoint file
there are number of things you need to consider, e.g. N/S E/W of the coordinates (usually it is represented with -) does it affect the length? also decimal precision - you may need to round the float number for lon/lat to correct precision)