Pyserial again

[luca72]

Hello here is a part of code, the values for settings comes from combo
box:

here i take the ATR of the smartcard inserted in the reader, and than i
store the read data in a textctrl.
Sniffing the data with serial port monitor i see that the answer is ok
but after the answer the port close, why?
Another point is the textctrl: it store only the first byte and not the
other why?, the byte are like 22 and all are readed

Thaks

ser = serial.Serial(porta)
        ser.baudrate = (atr)
        ser.parity = (parity)
        ser.stopbits = (stop)
        ser.bytesize = (size)
        ser.setRTS(level = 0)
        ser.setDTR(level = 0)
        ser.timeout = (time)
        a = ser.readline()
        a = self.textCtrl3.SetValue(a + ' ')
        self.lettura()
        ser.setBaudrate(baud)