NameError: name '__main__' is not defined

[Peng Yu]

Hi,

I try the following code. I don't quite understand why __main__ is not
defined. Could somebody let me know what I am wrong about it?

Regards,
Peng

$ cat test.py
#!/usr/bin/env python

if __main__ == '__main__' :
  print "Hello World!\n"
$ ./test.py
Traceback (most recent call last):
  File "./test.py", line 3, in <module>
    if __main__ == '__main__' :
NameError: name '__main__' is not defined