running a persistent python script from systemd?

I have a python script that decodes the input from a usb device and sends commands to a php script. The script works beautifully when run from the console, but I need it to be run on startup.

I created a systemd service to start the script, which appears to work well, except that the systemctl start service-name process never returns me to the command prompt. While it is running, I can interact with the input device, exactly as expected. However, if I exit the systemctl start process with ctr-z, the script only remains running for a few seconds.

Here is the .service file that I wrote:

[Unit]
After=default.target

[Service]
ExecStart=/usr/bin/python /root/pidora-keyboard.py

[Install]
WantedBy=default.target

and here is my python script:

#!/usr/bin/env python
import json, random
from evdev import InputDevice, categorize, ecodes
from urllib.request import urlopen

dev = InputDevice('/dev/input/event2')

def sendCommand(c):
    return json.loads(urlopen("http://127.0.0.1/api.php?command="+c).read().decode("utf-8"))
def getRandomStation():
    list = sendCommand('stationList')
    list = list['stations']
    index = random.randint(0, (len(list)-1))
    print(list[index]['id'] + " - " + list[index]['name'])
    sendCommand('s' + list[index]['id'])

print(dev)
for event in dev.read_loop():
    if event.type == ecodes.EV_KEY:
        key_pressed = str(categorize(event))
        if ', down' in key_pressed:
            print(key_pressed)
            if 'KEY_PLAYPAUSE' in key_pressed:
                print('play')
                sendCommand('p')
            if 'KEY_FASTFORWARD' in key_pressed:
                print('fastforward')
                sendCommand('n')
            if 'KEY_NEXTSONG' in key_pressed:
                print('skip')
                sendCommand('n')
            if 'KEY_POWER' in key_pressed:
                print('power')
                sendCommand('q')
            if 'KEY_VOLUMEUP' in key_pressed:
                print('volume up')
                sendCommand('v%2b')
            if 'KEY_VOLUMEDOWN' in key_pressed:
                print('volume down')
                sendCommand('v-')
            if 'KEY_CONFIG' in key_pressed:
                print('Random Station')
                getRandomStation()

how do I make the script run asynchronously from the service file, so that the start command can complete, and the script can continue running in the background?