a piece of code found at https://www.microchip.com/forums/m758342.aspx that shows how to connect to an AP using python and RN171

rn171connect.py

 import serial   
 import os   
 import sys   
 import time  
 
 chunk_size = 5000   
 os.chdir("D:\govind\Python\RN-wifly")   
 
 print "Starting WiFly Comm"   
 # To change baudrate -> set uart baudrate 115200, then save <CR>, then reboot   
 print "Opening Port"   
 ser = serial.Serial(11, 9600, timeout=3,parity=serial.PARITY_NONE)   
 print ser.portstr       # check which port was really used   
 print "OpenResult ="   
 print ser.isOpen()   
 ser   
 #if(!ser.isOpen())   
 # Quit   
 # set uart baudrate 115200   
 # Enter Command mode   
 ser.write("$$$")   
 line = ser.readlines()   # read a '\n' terminated line   
 print "***"   
 print line   
 if("CMD\r\n" in line):   
     print "Commmand mode Entered"   
 ser.write("set uart mode 1\r\n")  # disable echo   
 line = ser.readlines()   # read a '\n' terminated line   
 print line   
 ser.write("set comm remote 0\r\n") # Disable the remote message   
 line = ser.readlines()   # read a '\n' terminated line   
 print line   
 ser.write("set wlan join 0\r\n") # Disable auto associate   
 line = ser.readlines()   # read a '\n' terminated line   
 print line   
 ser.write("get e\r\n") # Get the settings   
 line = ser.readlines()      
 print line   
 # Set WiFi Parameters   
 ser.flushInput()   
 ser.write("set wlan pass your_AP_passwordr\n")   
 line = ser.readlines()   
 print line   
 if("AOK\r\n" in line):   
     print "Password Set"   
            
 wifi = 0;   
 while(wifi == 0):   
     ser.write("scan\r\n")    
     line = ser.readlines()      
     print line   
     ser.flushInput()   
     ser.write("join your_AP_name\r\n")   
     line = ser.readlines()   
     print line   
     if("Associated!\r\n" in line):   
         print "Joined AP"   
         wifi = 1;