[Tutor] How to use a module when only import package

[leechau]

Steven wrote:
> leechau wrote:
>> I wrote module1 in package1, and want to use a method named 'method1' in
>> module1, the caller(test.py) is like this:
>>
>> import package1
>> package1.module1.method1()
> [...]
>> When i run test.py, the output is:
>> AttributeError: 'module' object has no attribute 'module1'
>> File "e:\MyDoc\GODU_BVT\test.py", line 2, in <module>
>>   package1.module1.method1()
>>
>> If test.py is modified to:
>> import package1.module1
>> ...
>> then everything goes well.
>
> Yes, that is correct, and that is a deliberate design.
>
> What if your package had a 1000 sub-modules, each of which were big? You
> wouldn't want loading the main package to automatically load all 1000
> sub-modules, if you only needed 1.
>
> You either import the sub-module by hand:
>
> import package1.module1
>
> and now you can use package1.module1.method1 (not really a method,
> actually a function). If you want module1 to automatically be available
> after importing the package, include one of these in the package1
> __init__.py file:
>
> import module1  # should work in Python 2
>
>
> and now package1 will include the module1 in its namespace.
>
>
> --
> Steven

Thanks for Steven's exellent and patient explanations. How should I do 
if automatically import a module in Python 3? Thanks again.

--
leechau