catch output of threads

[William]

Jeff Epler <jepler at unpythonic.net> writes:

> You can make sys.stdout an object which uses thread.get_ident() to do
> "something special" with data written depending on what thread wrote it.

Thanks, really brilliant idea !

> 
> "ThreadedOutputThing" just prefixes all lines of output with the
> thread ID.  "ThreadedOuputThing2" creates files that contain the PID
> and TID.  TOT2 keeps a cache of open file objects, but never has more
> than ten open at once.
> 
> You could do other things, depending on your needs.
> 
> Jeff
> 
> import sys, thread, time, os
> 
> class ThreadedOutputThing:
>     def __init__(self, f = sys.stdout):
>         self.f = f
> 
>     def write(self, s):
>         i = thread.get_ident()
>         print >>self.f, "Thread %5d: %r" % (i, s)
> 
> class ThreadedOutputThing2:
>     def __init__(self, b = "%d-%%d.out" % os.getpid(), of="a"):
>         self.b = b
>         self.of = of
>         self.d = {}
> 
>     def write(self, s):
>         i = thread.get_ident()
>         d = self.d
>         if not d.has_key(i):
>             if len(d) > 10:
>                 d.popitem()[1].close()
>             d[i] = open(self.b % i, self.of)
>         d[i].write(s)
> 
> def f():
>     print "In function f, thread %d" % thread.get_ident()
> 
> if __name__ == '__main__':
>     #sys.stdout = ThreadedOutputThing()
>     sys.stdout = ThreadedOutputThing2()
>     thread.start_new_thread(f, ())
>     thread.start_new_thread(f, ())
>     thread.start_new_thread(f, ())
>     time.sleep(1)
> 

-- 
William Dode - http://flibuste.net