with open('com1', 'r') as f:

[Kushal Kumaran]

On Thu, 2 Apr 2009 10:01:02 -0700 (PDT)
gert <gert.cuykens at gmail.com> wrote:

> from subprocess import *
> 
> check_call(['mode', 'COM1:9600,N,8,1,P'],shell=True)
> while True:
>     with open('com1', 'r') as f:
>         for line in f:
>              print('line')
> 
> This works very well except for one thing. After a reboot I have to
> launch 1 time any windows serial exe application no mater with one,
> that just opens an closes the com port, before i can launch this
> script. The script keeps on working even after closing and reopening
> it, until i reboot the pc. Then again I have to launch one time a
> serial.exe and close it again. The exe does not run anything in the
> background it just does something in windows python does not do when
> it reads from the com port after a fresh reboot.
> 
> And i really appreciate it if somebody knew what it was.

I don't know why you're getting this behaviour, but have you tried using
a python library for accessing the serial port? See
http://pyserial.wiki.sourceforge.net/pySerial.

-- 
kushal