2nd Try: Trouble writing lines to file that include line feeds - Newbie

Dan Healy daniel.t.healy at gmail.com
Mon Dec 23 04:09:34 CET 2013


Solved. Simply change the 'w' from the file.open method to an 'a' for append

On Sunday, December 22, 2013 7:55:28 PM UTC-5, Dan Healy wrote:
> Overview: I'm attempting to read strings from a serial port. Each string ends with a carriage return and line feed. I want to write those strings to a file, like a log file. So, if I send P1 and the P2 on a new line, I would expect to open this file and find (line 1) P1 (line 2) P2. 
> 
> 
> 
> Problem: The file only contains P2. It always overwrites the first line. I can send 20 strings and the file will always contain the last string received. 
> 
> 
> 
> Code: 
> 
> 
> 
> #Import the serial module 
> 
> import serial 
> 
> 
> 
> #Open the serial port w/ settings 
> 
> ser=serial.Serial( 
> 
>         port="/dev/ttyUSB0", 
> 
>         baudrate=9600, 
> 
>         timeout=None) 
> 
> 
> 
> #Print data received on the serial port after removing the CR and LF characters 
> 
> while True: 
> 
>         rawcode=ser.readline() 
> 
>         codelog=open('/home/pi/avdms/codes.log','w') 
> 
>         codelog.write(rawcode) 
> 
>         codelog.close()




More information about the Python-list mailing list