On 25 Oct, 2012, at 16:50, Tom Epperly <epper...@llnl.gov> wrote: > I am trying to work with Apple Mountain Lion's install of Python 2.7. I > have a language interoperability tool, Babel > http://www.llnl.gov/CASC/components/, that used embedded Python when > other languages are calling Python (c.g., C++ calling Python). My > fundamental problem is that sys.path is not being initialized the same > when I dlopen(libpython2.7.dylib) and initialize Python compared with > how the sys.path is set when the Python executable is called directly. > This causes Python to fail to load the numpy module used by Babel. > > bash-3.2$ /usr/bin/python2.7 -c "import sys; print sys.path; import > numpy"> /tmp/out1 > bash-3.2$ /usr/bin/python -c "import sys; print sys.path; import numpy" >> /tmp/out2 > bash-3.2$ cat /tmp/out1 > ['', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages', > '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old', > '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload', > '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC', > '/Library/Python/2.7/site-packages'] > bash-3.2$ diff /tmp/out1 /tmp/out2 > bash-3.2$ ls -al /usr/bin/python2.7 > lrwxr-xr-x 1 root wheel 75 Aug 23 11:10 /usr/bin/python2.7 -> > ../../System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7 > > Presumably, this C program that uses dlopen(), Py_Initialize, and > Py_SimpleString should have exactly the same output. > > /** foo.c */ > #include<dlfcn.h> > #include<stdio.h> > > int > main(int argc, char **argv) > { > // void *lptr = > dlopen("/System/Library/Frameworks/Python.framework/Python", RTLD_NOW | > RTLD_GLOBAL); > void *lptr = > dlopen("/System/Library/Frameworks/Python.framework/Versions/2.7/lib/libpython2.7.dylib", > RTLD_NOW | RTLD_GLOBAL); > if (lptr) { > void (*pyinit)(void) = dlsym(lptr, "Py_Initialize"); > if (pyinit) { > int (*runSimple)(const char *); > (*pyinit)(); /* initialize Python */ > runSimple = dlsym(lptr, "PyRun_SimpleString"); > if (runSimple) { > (*runSimple)("import sys ; print sys.path; import numpy"); > } > } > else { > fprintf(stderr, "Unable to locate Py_Initialize: %s\n", dlerror()); > } > } > else { > fprintf(stderr, "Error loading Python shared library: %s\n", > dlerror()); > } > } > > bash-3.2$ gcc foo.c ; ./a.out > ['/usr/lib/python27.zip', '/usr/lib/python2.7', > '/usr/lib/python2.7/plat-darwin', '/usr/lib/python2.7/plat-mac', > '/usr/lib/python2.7/plat-mac/lib-scriptpackages', > '/usr/Extras/lib/python', '/usr/lib/python2.7/lib-tk', > '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload'] > Traceback (most recent call last): > File "<string>", line 1, in<module> > ImportError: No module named numpy > > However as you see, it has a completely different sys.path. I can't seem > to find a way to get it to initialize Python with the same sys.path. It > seems like the libpython2.7.dylib is broken. I am at a loss on how to > fix this or even who to ask for help.
Not sure why this doesn't work, py2app uses simular code and that works fine. What's really odd: when I run this on my machine and print sys.prefix it shows that sys.prefix is /Library/Frameworks/Python.framework instead of /System/.... as I'd expect. When I move the Python framework in /Library/Frameworks aside the program gives the same output as your program, with sys.prefix set to '/usr'. Apple publishes the source code for the python version they ship, and when I look at <http://www.opensource.apple.com/source/python/python-60.3/2.7/fix/getpath.c.ed> I get the impression that they changed the way sys.prefix is located. Stock CPython uses a deprecated API and they appear to have switch that to using dlopen API. Ronald > > Regards, > > Tom Epperly > > _______________________________________________ > Pythonmac-SIG maillist - Pythonmac-SIG@python.org > http://mail.python.org/mailman/listinfo/pythonmac-sig > unsubscribe: http://mail.python.org/mailman/options/Pythonmac-SIG _______________________________________________ Pythonmac-SIG maillist - Pythonmac-SIG@python.org http://mail.python.org/mailman/listinfo/pythonmac-sig unsubscribe: http://mail.python.org/mailman/options/Pythonmac-SIG
