filter_nmea.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# By Marek Łukasiewicz 2019

filenames = ['GarminGoracy.txt', 'GarminZimny.txt', 'NovatelEgnos.txt', 'NovatelGoracy.txt', 'NovatelZimny.txt']

for filename in  filenames:
    infile = open(filename, 'r')
    out_gga = open('gga_' + filename, 'w')
    out_gsa = open('gsa_' + filename, 'w')

    for line in infile:
        if line[:6] == '$GPGGA':
            out_gga.write(line)
        elif line[:6] == '$GPGSA':
            out_gsa.write(line)

    infile.close()
    out_gga.close()
    out_gsa.close()