On 06/10/2015 16:31, Robin Becker wrote:
.........
well it seems someone can build these extensions properly. I used Christoph
Gohlke's reportlab build and although there are 3 failures in the latest tests I
don't see any crashes etc etc and all the failures are explainable. Last thing I
saw from him in respect of pyRXPU was to use extra_compile_args=['/Od']. I will
try that in the reportlab extension builds and see if the problems go away.
I figured out the problem I was having with windows vs python3.5. It seems that
something has changed in the way extensions are loaded when using imp to
override the normal import mechanism.
The following code works OK for python 2.7, 3.3 & 3.4, but fails fairly
catastrophically when used in a complex way (ie running reportlab's tests).
Simple usage appears to work ie when I run one test.
My extension loading code looks like this
######################################
def __hack__():
import sys, os, importlib, imp
if sys.modules['reportlab'].__path__[0].lower()!=r'c:\code\reportlab':
return
from distutils.util import get_platform
archname = get_platform()
_p0=r'c:\repos\reportlab\build\lib.%s-%d.%d' %
(archname,sys.version_info[0],sys.version_info[1])
_p1=r'c:\repos\pyRXP\build\lib.%s-%d.%d' %
(archname,sys.version_info[0],sys.version_info[1])
_overrides={
'reportlab.lib._rl_accel':os.path.join(_p0,r'reportlab\lib'),
'reportlab.graphics._renderPM':os.path.join(_p0,r'reportlab\graphics'),
'pyRXPU':_p1,
}
def find_override(name):
if name in _overrides and os.path.isdir(_overrides[name]):
fpd = imp.find_module(name.split('.')[-1],[_overrides[name]])
try:
try:
return imp.load_module(name,fpd[0],fpd[1],fpd[2])
except:
pass
finally:
if fpd[0]: fpd[0].close()
class RLImporter(object):
def __init__(self):
self.module = None
def find_module(self, name, path=None):
m = find_override(name)
if m:
m.__loader__ = self
self.module = m
return self
def load_module(self, name):
if not self.module:
raise ImportError("Unable to load module %s" % name)
sys.modules[name] = m = self.module
self.module = None
return m
sys.meta_path.insert(0, RLImporter())
__hack__()
del __hack__
######################################
My guess is that it's not cool any more to use imp.load_module repeatedly or
that the hack of passing the found module about using a temporary attribute is
not a good idea.
The intent of the above code is to allow me to build extensions for multiple
pythons in a single area under c:\repos\reportlab\build and allow loading of
those with different python versions. I don't want to pollute my repository with
different extensions so prefer to keep them in the build area (and they change
very slowly compared to the python code).
Is there some simple sample code that can be used as a model for this. I've
tried looking at the importlib docs and my brain is bursting. I also looked at
http://chimera.labs.oreilly.com/books/1230000000393/ch10.html, but that seems
all about normal python models/packages.
I think importlib has split the loading of extensions into a different method,
and there seem to be assertions about re-using an existing loader.
--
Robin Becker
--
https://mail.python.org/mailman/listinfo/python-list
