I think the first time I've launched the program it showed me similar error.
But after program restart it connected successfully
python3 ./main.py
qt5ct: using qt5ct plugin
swcccv_reset
instruments
ASRL/dev/ttyS0::INSTR
SerialInstrument at ASRL/dev/ttyS0::INSTR
probe
no answer
ko
ASRL/dev/ttyUSB0::INSTR
SerialInstrument at ASRL/dev/ttyUSB0::INSTR
probe
found PX100
readAll
'is_on': 0.0, 'voltage': 0.0, 'current': 0.0, 'time': datetime.time(0, 0), 'cap_ah': 0.0, 'cap_wh': 0.0, 'temp': 29.0, 'set_current': 0.0, 'set_voltage': 0.0, 'set_timer': datetime.time(0, 0)}