Question

I try to use __init__.py.

My directory:

 sam@sam-M51Kr:~/code/python$ tree
 .
 |-- __init__.py
 |-- lib
 |   |-- __init.py
 |   |-- sam_lib.py
 |   `-- sam_lib.pyc
 `-- test.py

 1 directory, 5 files
 sam@sam-M51Kr:~/code/python$

All my __init__.py are empty.

My lib/sam_lib.py:

k='hello!'

My test.py:

import python.lib.sam_lib
print(sam_lib.k)

When I run:

 sam@sam-M51Kr:~/code/python$ python test.py 
 Traceback (most recent call last):
   File "test.py", line 1, in <module>
     import python.lib.sam_lib
 ImportError: No module named python.lib.sam_lib
 sam@sam-M51Kr:~/code/python$

How to solve it with syntax import x.x?

Should I use __init.py__?

==============================

I revise lib/__init.py to lib/__init__.py

I try to revise test.py:

 from . import lib.sam_lib as sam_lib
 print(sam_lib.k)

It will cause an error:

 sam@sam-M51Kr:~/code/python$ python test.py 
   File "test.py", line 1
     from . import lib.sam_lib as sam_lib
                      ^
 SyntaxError: invalid syntax
 sam@sam-M51Kr:~/code/python$

And it is ok when I revise to:

 import lib.sam_lib as sam_lib
 print(sam_lib.k)

Answer 1

Your code is wrong at different levels

• The file __init.py should be __init__.py
• In python, you need to access object with its relative path: when you do import a.b.c the
  c.x object must be accessed using a.b.c.x unless you used import
a.b.c as c

To fix the code, use:

import lib.sam_lib as sam_lib
print(sam_lib.k)

Note that import python.lib.sam_lib as sam_lib or from .lib import sam_libwould have worked if test.py is imported as a module as in import python.test from a code in the upper level directory, not when you run test.py directly.