在Stackoverflow上问了个关于import的问题 没什么人回答 转到这里 望解答

就不翻译啦 很浅的英语

The following is structure of my program

./abc.py

./a/__init__.py

./b/__init__.py

./b/t.py

Source code of abc.py

=============
import a
=============

Source code of ./a/__init__.py

=======================
from b import t
=======================

Source of of ./b/t.py

=================
def aa():
print "bbb"
=================

./b/__init__.py is an empty file.

There is a statement

========
t.aa()
========

if I put it into ./a/__init__.py, then when I run abc.py, it works fine. But if I put it into abc.py, when I run the script, I get an error like

Traceback (most recent call last): File "abc.py", line 3, in t.aa() NameError: name 't' is not defined

What's the reason of this? Thank you in advance.