Python function works fine except when imported

Question

I've tried to distill this to the essentials. This code works fine.

from evdev import InputDevice, ecodes
dev = InputDevice('/dev/input/event2')   # this is the joystick event file
button = {304: 'A', 305: 'B', 307: 'X', 308: 'Y' }  # Xbox360 button mappings
exit = False

def joystick(dev):
    try:
        for event in list(dev.read()):
            if button[event.code] == 'A' and event.value == 1:
                print('Button A pressed.')
            if button[event.code] == 'X' and event.value == 1:
                print('Button X pressed.')
                return True
    except: pass
    return False
    
while exit == False:
    exit = joystick(dev)

However, if I move the joystick function to a separate file (including the proper evdev import) and import it the code breaks (function "joystick" will always return false, not recognizing joystick events).

Any ideas why? I know the software/hardware interface can be tricky but this is ridiculous.

Try removing the `try` block and see what causes the function to return `False`. — Maximilian Peters, Nov 14 '20 at 19:40
The ```try``` is necessary because if there are no events to process an error is thrown and execution stops. — user52326, Nov 14 '20 at 19:49
Try to catch only the specific exception you are expecting, currently you catch everything which might mask the error. — Maximilian Peters, Nov 14 '20 at 19:50

score 0 · Answer 1 · answered Nov 14 '20 at 20:56

0

Found the bug. When I moved the joystick function outside of the file I neglected to port the button dictionary with it. The try statement masked the error I normally would have gotten by omitting the dictionary.

answered Nov 14 '20 at 20:56

user52326

11
2

Python function works fine except when imported

1 Answers1