Basic loop for reading RFID tags. Filters out unwanted characters and ignores reads that happen back to back.

rfid.py

import serial
import datetime

ser = serial.Serial('/dev/ttyUSB0', 2400, timeout=1)
count = 0
read_time = datetime.datetime.now()
last_read = 'asdfasdf' #trash string so initial comparison fails
while True:
  line = ser.readline()
    if len(line) > 1:
        line = line.replace('\n','').replace('\r','')
        if line == last_read:
            if datetime.datetime.now() - datetime.timedelta(seconds=2) < read_time:
                continue
        count += 1
        last_read = line
        print {
            'length': len(line),
            'count': count,
            'tag_id': line
        }
        read_time = datetime.datetime.now()

pySerial, get it!