Strangeness: Cannot write to a file from a process created by Windows Task Scheduler ...

Sandy Walsh swalsh at
Mon Oct 26 18:17:08 CET 2009

Hi there,

Seeing some really weird behavior and perhaps someone has seen something 

I have a python script that launches as a Windows Scheduled Task. The 
program simply opens a disk file and writes some text to it:

f = open("waiting.txt", "w")
x = 0
while 1:
    f.write("Sleeping: %d\r\n" % x)
    x += 1


I've run it under my user account. I've run it as Local Account. I've 
run it via pythonw and python ... only one way works:

When I run with full credentials (not local account) and python (not 
pythonw) I get output in the file (and a CMD window appears while it's 
running). In every other combination it creates the 'waiting.txt' file, 
but doesn't write any output to the file. The length of the file is 0 bytes.

Anyone have ideas what could be causing this? I suspect it's blocking on 
something, but I can't imagine where.

There is no stderr/stdout output anywhere in the program so it's not 
blocking on anything stdio related (that I can imagine)


-------------- next part --------------
A non-text attachment was scrubbed...
Name: swalsh.vcf
Type: text/x-vcard
Size: 326 bytes
Desc: not available
URL: <>

More information about the Python-list mailing list