C里import python模块出错，请帮忙看一下

CODE:

#########################################################
# C runs Python code in this module in embedded mode.
# Such a file can be changed without changing the C layer.
# There is just standard Python code (C does conversions).
# You can also run code in standard modules like string.
#########################################################

message = 'The meaning of life...'

def transform(input):
    input = input.replace('life', 'Python')
    return input.upper( )

CODE:

/*******************************************************
* simple code strings: C acts like the interactive
* prompt, code runs in _ _main_ _, no output sent to C;
*******************************************************/
#include <Python.h>    /* standard API def */
#include <stdio.h>

main( ) {
    printf("embed-simple\n");
    Py_Initialize( );
    PyRun_SimpleString("import os");                /* load .py file */
    printf("pwd\n");
    PyRun_SimpleString("os.system('pwd')");                /* print working directory */
    PyRun_SimpleString("import usermod");                /* load .py file */
    PyRun_SimpleString("print usermod.message");         /* on Python path */
    PyRun_SimpleString("x = usermod.message");           /* compile and run */
    PyRun_SimpleString("print usermod.transform(x)");
}

CODE:

# a Cygwin makefile that builds a C executable that embeds
# Python, assuming no external module libs must be linked in;
# uses Python header files, links in the Python lib file;
# both may be in other dirs (e.g., /usr) in your install;

PYLIB = /usr/bin
PYINC = /usr/include/python2.4

embed-simple: embed-simple.o
        gcc embed-simple.o -L$(PYLIB) -lpython2.4 -g -o embed-simple

embed-simple.o: embed-simple.c
        gcc embed-simple.c -c -g -I$(PYINC)

CODE:

/Integrate/Embed/Basics$ ./embed-simple
embed-simple
pwd
/Integrate/Embed/Basics
Traceback (most recent call last):
  File "<string>", line 1, in ?
ImportError: No module named usermod
Traceback (most recent call last):
  File "<string>", line 1, in ?
NameError: name 'usermod' is not defined
Traceback (most recent call last):
  File "<string>", line 1, in ?
NameError: name 'usermod' is not defined
Traceback (most recent call last):
  File "<string>", line 1, in ?
NameError: name 'usermod' is not defined