[split] Check presence of a file

[snippsat]

The code you have posted of function read_sensor(sensorID) missing : SyntaxError.
The read read_sensor(sensorID) should also return a value as you need that later when comparing.

def read_sensor(sensorID):
    tempfile = open("/sys/bus/w1/devices/"+ sensorID +"/w1_slave")
    thetext = tempfile.read()
    tempfile.close()
    tempdata = thetext.split("\n")[1].split(" ")[9]
    temperature = float(tempdata[2:])
    temp_sensor = temperature / 1000
    return temp_sensor  # Not print()

57.0
35.875
Traceback (most recent call last):
File "temp.py", line 10, in <module>
read_sensor(sID1) > read_sensor(sID2)
TypeError: unorderable types: NoneType() > NoneType()

When read_sensor function has no return value only print(),it will return None.