UBUNTU HOST:

$ which python
/usr/bin/python
$ python
Python 2.7.3 (default, Feb 27 2014, 20:00:17) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import bb
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named bb
>>> import polib
>>> 


POKY:

$ which python
/opt/poky/1.5.1/sysroots/i686-pokysdk-linux/usr/bin/python
$ python
Python 2.7.3 (default, Dec 14 2013, 11:50:58) 
[GCC 4.8.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import bb
>>> import polib
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named polib
>>> 

$ export PYTHONPATH=$PYTHONPATH:/usr/local/lib/python2.7/dist-packages/
$ python
Python 2.7.3 (default, Dec 14 2013, 11:50:58) 
[GCC 4.8.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import bb
>>> import polib
>>> 



BITBAKE (WITH POKY):

ERROR: Please install polib (e.g. 'pip install polib' or by using your favorite distro's package manager)