Antoine Pitrou wrote: > Barry Warsaw <barry <at> python.org> writes: >>> exarkun <at> boson:~$ python -m timeit -s 'from os import getcwd' 'getcwd()' >>> 1000000 loops, best of 3: 1.02 usec per loop > [...] >> I'd like to see the effect on command line scripts that are run often and >> then >> exit, e.g. Bazaar or Mercurial. Start up time due to import overhead seems >> to >> be a constant battle for those types of projects. > > If os.getcwd() is only called once when "normalizing" sys.path, and if it just > takes one microsecond, I don't really see the point. :-)
The problem is that having '' as the first entry in sys.path currently means "do the import relative to the current directory". Unless we want to change the language semantics so we stick os.getcwd() at the front instead of '', then __file__ is still going to be relative sometimes. Alternatively, we could special case those specific imports to do os.getcwd() at the time of the import. That won't affect the import speed significantly for imports from locations other than '' (i.e. most of them) and will more accurately reflect the true meaning of __file__ in that case (since we put the module in sys.modules, future imports won't see different versions of that module even if the working directory is changed, so the relative value for __file__ becomes a lie as soon as the working directory changes) Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia --------------------------------------------------------------- _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
