from_serial_to_file.py

import serial
import argparse


parser = argparse.ArgumentParser()
parser.add_argument("-p", "--port", type=str,
                    help="name of port",
                    default='/dev/ttyUSB0')
parser.add_argument("-o", "--output_filename", type=str,
                    help="filename of output file",
                    default='data.txt')


def main():
    args = parser.parse_args()
    port = args.port
    output = args.output_filename

    ser = serial.Serial(port, 9600, timeout=1)
    with open(output, 'a+') as f:
        while True:
            line = ser.readline()   # read a '\n' terminated line
            f.write(line)
        ser.close()

if __name__ == '__main__':
    main()

Simple script for reading from serial.

Reads from serial on selected port and writes to file.

usage:

$ python from_serial_to_file.py [-h] [-p PORT] [-o OUTPUT_FILENAME]

optional arguments:
-h, --help show this help message and exit
-p PORT, --port PORT name of port
-o OUTPUT_FILENAME, --output_filename OUTPUT_FILENAME
filename of output file