源代码文件

1.test_main.py

#!/usr/bin/python

if __name__ == "__main__":
    print "I am the main program."
else:
    print "Someone is importing me."

运行结果：

2.echo.py

#!/usr/bin/python
import test_main
print "echo: __name__ is", __name__

运行结果：

3.import_echo.py

#!/usr/bin/python

import echo
print "After import, __name__ is", __name__, "and echo.__name__ is", echo.__name__

运行结果：