Python example only works with ASCII event

[rm5248]

Describe the bug
Using the sample python application, changing the CardFormat to anything except 'ASCII' throws an error. The event:

card_event = {
    'event': Event.CardRead,
    'reader_no': 1,
    'direction': 1,
    'format': CardFormat.ASCII, <-- change this to CardFormat.Wiegand to reproduce
    'data': bytes([9,1,9,2,6,3,1,7,7,0]),
}

Expected behavior
exceptions are not thrown

Observed behavior

$ ./pd_orig.py --baudrate 9600  --log-level 7 /dev/ttyUSB1
OSDP: PD-0: 2025-12-12T17:13:21Z   osdp_pd.c:1184 [WARN ] SCBK not provided. PD is in INSTALL_MODE
pyosdp: 2025-12-12T17:13:21Z   osdp_pd.c:1202 [INFO ] PD Setup complete; LibOSDP-3.1.0 master (v3.1.0)
OSDP: PD-0: 2025-12-12T17:13:21Z  osdp_phy.c:581  [DEBUG] Packet scan skipped:2 mark:1
OSDP: PD-0: 2025-12-12T17:13:22Z   osdp_pd.c:699  [DEBUG] CMD: CAP(62) REPLY: PDCAP(46)
OSDP: PD-0: 2025-12-12T17:13:22Z   osdp_pd.c:699  [DEBUG] CMD: ID(61) REPLY: PDID(45)
OSDP: PD-0: 2025-12-12T17:13:22Z   osdp_pd.c:699  [DEBUG] CMD: COMSET(6e) REPLY: COM(54)
PD: Received command: {'command': 6, 'address': 0, 'baud_rate': 9600}
OSDP: PD-0: 2025-12-12T17:13:22Z   osdp_pd.c:1086 [INFO ] COMSET Succeeded! New PD-Addr: 0; Baud: 9600
Traceback (most recent call last):
  File "/home/robert/CE-reader-issues/./pd_orig.py", line 76, in <module>
    pd.submit_event(card_event)
  File "/home/robert/CE-reader-issues/venv/lib/python3.11/site-packages/osdp/peripheral_device.py", line 69, in submit_event
    ret = self.ctx.submit_event(event)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: Unable to get event struct!

Additional context
libosdp was installed through pip.

Also, this shows a problem with the current code: in the submit_event function, because the exception is being thrown the mutex is never being unlocked, thus locking up the entire system. The code needs to use a context manager in order to lock/unlock, something like this to ensure that the lock is released if there is an error:

    def submit_event(self, event):
        with self.lock:
            ret = self.ctx.submit_event(event)
        return ret

[rm5248]

Note: I realized after that the problem was that i was missing the length field in the card_event dict. Once I fixed that it started working, but the lock problem and the unclear error message are still issues.