Im trying to import a sage package (var) in a python file

```
from sage.all import var
```

but when run the file Im getting this error :

```
Error
Traceback (most recent call last):
execfile("/home/sagefolder/SageMath/myapp/core/test.sage")
File "/home/sagefolder/SageMath/ubbr/engine/test.py", line 20, in <module>
from sage.all import var
File "/home/sagefolder/SageMath/local/lib/python2.7/site-packages/sage/all.py", line 71, in <module>
from sage.env import SAGE_ROOT, SAGE_SRC, SAGE_DOC_SRC, SAGE_LOCAL, DOT_SAGE, SAGE_ENV
File "/home/sagefolder/SageMath/local/lib/python2.7/site-packages/sage/env.py", line 123, in <module>
_add_variable_or_fallback('SAGE_ETC', opj('$SAGE_LOCAL', 'etc'))
File "/home/sagefolder/SageMath/local/lib/python2.7/site-packages/sage/env.py", line 103, in _add_variable_or_fallback
value = sep.join(components)
TypeError: sequence item 0: expected string, NoneType found
```

my guess was that the problem was related to the env path. but even

```
sys.path.append('/path/to/the/sage/')
```

it does not work

I would be pleased if anybody can help me as Im doing an important project and I really need to use sage.