[Tutor] Looping problem

[vicki at thepenguin.org]

Okay, I am trying to parse some data which looks something like this:


  ab<TAB><TAB>11<CR><ACK>
  <STX>04142069<ETX><ACK>
  <STX>08000000006E<ETX><ACK>
  <STX>0414106A<ETX><ACK>
  <STX>10169100000000000061<ETX><ACK>
  <STX>10169000000000000060<ETX><ACK>
  <STX>1016934129CD4CCB201E<ETX><ACK>
  <STX>10169200000000000062<ETX><ACK>
  <STX>10169500000000000065<ETX><ACK>
  <STX>10169400000000000064<ETX><ACK>
  <STX>20170000000281082A07D4021A0000000815<EOT><ACK><ACK>

What I need to do is move to the point just after the ab command, and then
send an '\x02' for each <STX>, send an '\x03' for each <ETX>, read in each
<ACK> after sending the <ETX>, and recognize when I reach the end of data
and send an '\x04' for the <EOT> and receive the two <ACK>s. I wrote the
following:


        LTRD_START = False
        LTRD_END = False

        for readString in infile.readlines():
            word = ""
	    #Find our place in the input file
            if re.search("Load Time Resolve Data",readString):
                LTRD_START = True
            else:
                if re.search("ab<TAB><TAB>11<CR><ACK>",readString):
                    print "Do Nothing"
                elif LTRD_START:
	            #Strip off beginning whitespace
                    readString.lstrip()
		    #Strip off <STX> and send [02] on port
                    s = string.lstrip(readString)
                    readString = string.lstrip(s,'<STX>')
                    port.write('\x02')
                    print readString

	            #Reset loop variable
                    INSIDE = False
	            #While not at the end of the data
                    while not LTRD_END:
                        for byte in readString:
			    #Check to see if it is a comm word like <STX>
                            if byte == '<':
                                INSIDE = True
                                word = byte
                            elif INSIDE and byte != '>':
                                word += byte
                            elif INSIDE and byte == '>':
                                word += byte
			       #Check to see if this is the end of the data
                                if word == '<ETX>':
				    port.write('\x03')
				    result = port.read()
				elif word == '<EOT>':
                                    LTRD_END = True
				    result = port.read()
				    print result
				    result = port.read()
				    print result
                                    break
				#Since this is the end of a comm word,
			        #reset the loop variable
                                INSIDE = False
                            elif INSIDE == False:
                                port.write(byte)

But I've got something wrong, because it loops infinitely and doesn't kick
out when it hits the <EOT>. Can anyone else see it?

Vicki

"A pessimist sees the difficulty in every opportunity; an optimist sees
the opportunity in every difficulty."
-- Winston Churchill