Install cx_Oracle on Ubuntu from rpm package

Make sure that you have installed Oracle instant client. If not, please follow this post.
1. make sure that the path in your oracle.conf file contains libclntsh.so.11.1 file

cat /etc/ld.so.conf.d/oracle.conf
#it shows
/usr/lib/oracle/11.2/client64/lib
# verify that the path contains libclntsh.so.11.1
ll /usr/lib/oracle/11.2/client64/lib | grep libclntsh
lrwxrwxrwx 1 root root        17 Aug  5  2013 libclntsh.so -> libclntsh.so.11.1
-rw-r--r-- 1 root root  52761218 Sep 17  2011 libclntsh.so.11.1

2. update ld.so.cache

sudo ldconfig

3. download and install cx_Oracle library from rpm package

sudo alien -i cx_Oracle-5.1.2-11g-py27-1.x86_64.rpm

4. Configure cx_Oracle to work with Python2.7 within Ubuntu

cd /usr/lib/python2.7
sudo mv site-packages/cx_Oracle* dist-packages/
sudo rmdir site-packages/
sudo ln -s dist-packages site-packages