Thread: Making Python faster (for fmms initially)
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Khertan is offline Khertan
2010-04-22 , 19:05
Posts: 1,012 | Thanked: 817 times | Joined on Jul 2007 @ France
#18
Nouvelle note 47

Originally Posted by TheBootroo View Post
use C++/Qt4 instead of PyQt
I'm askin for a ban for a such stupid comment !

Please consider that a laucher use memory and in some case can be slower.

Anyway ... there is simple things to optimize python scripts :

- When available, prefer module methode instead of self made in python, as most of module are in c. So really faster
- Avoid when possible too much search in namespace and prefer local method variables it s faster to assign a methode from namespace in a local var when it s called in a loop with more than 10 iterations
- abuse of profile to see where your code is leaking time (available on device)
- abuse of pylint
- instead of doing many test case, use exception : a simple example :
Code:
  if (mydiv#0):
    res=res/mydiv
  else:
    res=0
use:
Code:
  try:
    res=res/mydiv
  except NullDivisionError,e:
    res=0
- memorize pattern can help
- avoid cos , sin and tan in a game , use a precalculate array (for vectormine it s optimize fps from 3fps to 60fps)
- and again abuse of profile
- avoid converting data type in loop... Example QString to str
- use existing module when available : PyGtKEditor do all his parsing in python ... it s can be slow on large file, khteditor do the things clearly faster by using some Qt native class.

An other things to doesn't freeze the ui and to not slow down the device by using intensive thread is to divide tasks in very small tasks and to use a sigleton with gidle :
Code:
import gobject

class _DeferClass(object):
  _calls=[]
  _ref=None
  def __new__(cls,*args,**kw):
    if cls._ref is None:
      cls._ref = super(_DeferClass,cls).__new__(cls,*args,
                                                    **kw)
    return cls._ref

  def __len__(self):
    return len(self._calls)

  def __call__(self,func,*args):
    def NextCall():
      (func,args)=self._calls[0]
      func(*args)
      self._calls=self._calls[1:]
      return self._calls!=[]
    if not self._calls: gobject.idle_add(NextCall)
    self._calls.append((func,args))
I ve many example to give and there is so man things to say that i ll be able to write a book about py opimization.

So if you need so help optimizing code i can maybe help you.
__________________
Benoît HERVIER, Khertan
KhtEditor - Sdist_Maemo - Khweeteur - PyPackager - KhtSimpleText - KhtNotes - KhtBMA - Wleux - and more ...
Last edited by Khertan; 2010-04-26 at 12:30.
 

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