pyserial

[Mimi]

Hi,
I use the pyserial to read data from a serial port.
My code is in window Xp and python 2.4. when I use Hyperteminal I can
read data without try and try again that it is not the case with
pyserial library.
anyone can help me ?
this is a part of my code:

self.ser = serial.Serial()
    self.ser.baudrate = 9600
            self.ser.port = 3
            self.ser.timeout= 10
            self.ser.bytesize = serial.EIGHTBITS
            self.ser.stopbits = serial.STOPBITS_ONE
            self.ser.xonxoff = 0

   nbHisto = 144
   for i in range(0,nbHisto):
                while 1:
                    print self.ser.flushInput()
                    print self.ser.flushOutput()
                    cmd = "%xs\r" %(i+1)
                    self.ser.write("%s" %cmd)

                    #print cmd

                    histo = self.ser.readlines()
                    #print histo
                    if histo:
                        if histo=="\r\n":
                            pass
                        else:

                            histoAdresse = int(histo[0].strip('\r\n'))
                            print histoAdresse

                            try:
                                dateHisto_cur = listeFenetreNonNul["%s"
%(histoAdresse)]
                                print dateHisto_cur


self.ecrireHistoDansFic(histo,histoAdresse,dateHisto_cur,histoAdresse,i)
                                break
                            except:

                                print "Adresse pas trouvee dans le
systeme %s" %(histoAdresse)
                                break
                    # End if

                    sleep(10)
                # End while
            #End for

            
            self.ser.close()