Embedding Example

[Leonardo B. Lopes]

I am trying to learn how to embed Python code in a C++ program. I got
the example from the docs (the one that imports sys and prints out a
couple of strings -- search from initxyzzy in google). The problem I get
is that if I try to import any non-built in module, I get dynamic
linking errors. For example, adding the following line 31 works:

_______________________________________________________________________
...
     29         /* Execute some Python statements (in module __main__)
*/
     30         PyRun_SimpleString("import sys\n");
-->  31         PyRun_SimpleString("import thread\n");
     32         PyRun_SimpleString("print sys.builtin_module_names\n");
...
_______________________________________________________________________

but adding the following line instead:

_______________________________________________________________________
...
     29         /* Execute some Python statements (in module __main__)
*/
     30         PyRun_SimpleString("import sys\n");
-->  31         PyRun_SimpleString("import random\n");
     32         PyRun_SimpleString("print sys.builtin_module_names\n");
...
_______________________________________________________________________

produces:

_______________________________________________________________________
[lopes at groucho lopes]$ ./demo 
Hello, brave new world

Traceback (innermost last):
  File "<string>", line 1, in ?
  File "/usr/lib/python1.5/random.py", line 22, in ?
    import whrandom
  File "/usr/lib/python1.5/whrandom.py", line 140, in ?
    _inst = whrandom()
  File "/usr/lib/python1.5/whrandom.py", line 46, in __init__
    self.seed(x, y, z)
  File "/usr/lib/python1.5/whrandom.py", line 58, in seed
    import time
ImportError: /usr/lib/python1.5/lib-dynload/timemodule.so: undefined
symbol: PyExc_IOError
('__builtin__', '__main__', 'imp', 'marshal', 'pcre', 'posix', 'regex',
'signal', 'sys', 'thread')
['xyzzy', 'os.path', 'os', 'exceptions', '__main__', 'posix',
'whrandom', 'sys', '__builtin__', 'site', 'random', 'signal',
'UserDict', 'posixpath', 'stat']
./demo
['./demo']
_______________________________________________________________________

I can imagine that for some reason there is some directory configuration
missing to the interpreter when I start it embedded. How would I pass it
this info?

Thanks!
Leo.



-- 
========================================================================
Leonardo B. Lopes                                       leo at iems.nwu.edu 
Ph.D. Student                                              (847)491-8470
IEMS - Northwestern University              http://www.iems.nwu.edu/~leo