Python: How to read() on COM port until specifik string?

Question

I'm making a Python program for automatic setup of a modem using AT-commands (not important to know what that is)

I use the serial module for COM port communication.

The way it works is that i send a command, and then I want to "save" the respons until a string saying "OK" comes in the end. I tried this:

import serial
ser = serial.Serial(port='COM15', baudrate=115200, timeout=3, parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE)
intline =''
ser.write('AT+COPS?'+'\r\n')    '''This specific commands asks for network status'''
while ser.inWaiting() >0:
    intline += ser.read(1)
if 'Greentel' in intline:
    print "Internet access"
else:
    print "No internet access"

My trouble is that sometimes I get multiple lines in respons. As an example, for the command used here I get the respons:

"+UMWI: 0,4

+UMWI: 0,5

AT+COPS?

+COPS: 0,0,"Greentel",7

OK"

What I really want is to make a function who I can call to read until it meets OK, put the text in a string/list, and let me search for specific words in it.

Answer 1

Figured I'd post my solution for the slim chance of others working with AT commands in Python. What I did was make a function who reads the input and stores it in a string until a chosen stopsign is encountered. I made it like this:

def read2sign(command, stopSign):
ser.flushInput()
temp = ''
ser.write(command +'\r\n')
while stopSign not in temp:
    temp += ser.read(1)
    print "---"     '''For debugging purpose'''
    print temp
print temp
return temp

I also kinda want to say sorry for posting prematurely. I guess I just had to try longer :-)