Do you have profiling data to support your claim?
On Fri, Jun 25, 2010 at 7:48 PM, email@example.com wrote:
I'm interested in a feature which allows users to discard the locals and globals references from frames held by a traceback object.
Currently, traceback objects are used when capturing and re-raising exceptions. However, they hold a reference to all frames, which hold a reference to their locals and globals. These are not needed by the default traceback output, and can cause serious memory bloat if a reference to a traceback object is kept for any significant length of time, and there are even big red warnings in the Python docs about using them in one frame. ( http://docs.python.org/release/3.1/library/sys.html#sys.exc_info ).
Example usage would be something like:
import sys try: 1/0 except: t, v, tb = sys.exc_info() tb.clean() # ... much later ... raise t, v, tb
Which would be basically a function to do this:
import sys try: 1/0 except: t, v, tb = sys.exc_info() c = tb while c: c.tb_frame.f_locals = None c.tb_frame.f_globals = None c = c.tb_next # ... much later ... raise t, v, tb
Twisted has done a very similar thing with their twisted.python.failure.Failure object, which stringifies the traceback data and discards the reference to the Python traceback entirely ( http://twistedmatrix.com/trac/browser/tags/releases/twisted-10.0.0/twisted/p... ) - they also replicate a lot of traceback printing functions to make use of this stringified data.
It's worth noting that cgitb and other applications make use of locals and globals in its traceback output. However, I believe the vast majority of traceback usage does not make use of these references, and a significant penalty is paid as a result.
Is there any interest in such a feature?
-Greg _______________________________________________ Python-ideas mailing list Pythonfirstname.lastname@example.org http://mail.python.org/mailman/listinfo/python-ideas