RFID reader

app.py

from evdev import InputDevice, categorize, ecodes
from select import select
dev = InputDevice('/dev/input/event20')

print(dev)

scancodes = {
    # Scancode: ASCIICode
    0: None, 1: u'ESC', 2: u'1', 3: u'2', 4: u'3', 5: u'4', 6: u'5', 7: u'6', 8: u'7', 9: u'8',
    10: u'9', 11: u'0', 12: u'-', 13: u'=', 14: u'BKSP', 15: u'TAB', 16: u'Q', 17: u'W', 18: u'E',
    19: u'R', 20: u'T', 21: u'Y', 22: u'U', 23: u'I', 24: u'O', 25: u'P', 26: u'[', 27: u']',
    28: u'CRLF', 29: u'LCTRL', 30: u'A', 31: u'S', 32: u'D', 33: u'F', 34: u'G', 35: u'H',
    36: u'J', 37: u'K', 38: u'L', 39: u';', 40: u'"', 41: u'`', 42: u'LSHFT', 43: u'\\', 44: u'Z',
    45: u'X', 46: u'C', 47: u'V', 48: u'B', 49: u'N', 50: u'M', 51: u',', 52: u'.', 53: u'/',
    54: u'RSHFT', 56: u'LALT', 100: u'RALT'
}

full_string = ''

while True:
    r, w, x = select([dev], [], [])
    for event in dev.read():
        if event.type == ecodes.EV_KEY:
            data = categorize(event)
            if data.keystate == 1:  # Down event
                key_lookup = scancodes.get(data.scancode) or u'UNKNOWN:{}'.format(data.scancode)
                if key_lookup != 'CRLF':
                    full_string += key_lookup
                else:
                    print(full_string)
                    full_string = ''