I managed to do the example from what you gave and I got the results as it is. but, after several checking, I received bytes from the uart. Then, I need to convert to hex. the method i used is:

hexVal = hex(int.from_bytes(serData, "big"))
label14.set_text(str(hexVal)) //to show the hexVal to the label

I got the idea from the example you gave and THANK YOU so much for that =)

You can try this way:

a = "0x0A"
b = int(a, 16)
print(b)

docs is here: link