Installing Python 2.7 on CentOS 6.5

python27_on_centos65.md

Installing Python 2.7 on Centos 6.5

Centos 6.* comes with Python 2.6, but we can't just replace it with v2.7 because it's used by the OS internally (apparently) so you will need to install v2.7 (or 3.x, for that matter) along with it. Fortunately, CentOS made this quite painless with their Software Collections Repository

sudo yum update # update yum
sudo yum install centos-release-scl # install SCL 
sudo yum install python27 # install Python 2.7

To use it, you essentially spawn another shell (or script) while enabling the newer version of Python:

scl enable python27 bash

To install additional libraries, you will need to install PIP:

cd /opt/rh/python27/root/usr/bin/ # cd to the directory where SCL installs python
sudo LD_LIBRARY_PATH=$LD_LIBRARY_PATH ./easy_install-2.7 pip

once installed, you can install PIP using pip2.7, e.g.:

sudo LD_LIBRARY_PATH=$LD_LIBRARY_PATH ./pip2.7 install requests 

NOTE: if your username doesn't require root to install software, then LD_LIBRARY_PATH and PATH is set up for you automatically by scl. Also keep in mind that using SCL outside a shell (e.g., cronjobs) isn't quite straightforward. Also, using virtualenv poses a challenge as well.

When running pip I ran into a problem with permissions, it gave me this error any time I tried do any pip command:

$ ./pip2.7 -V
Traceback (most recent call last):
  File "./pip2.7", line 7, in <module>
    from pip import main
  File "/opt/rh/python27/root/usr/lib/python2.7/site-packages/pip/__init__.py", line 21, in <module>
    from pip._vendor.requests.packages.urllib3.exceptions import DependencyWarning
ImportError: No module named requests.packages.urllib3.exceptions

I found out that this was due to permissions problems on the lib folders. To fix it I had to add the read and execute permissions to the python lib and lib64 folders like:
sudo chmod -R o+rx /opt/rh/python27/root/usr/lib/python2.7/site-packages

For this error: Error: python2.7: error while loading shared libraries: libpython2.7.so.1.0: cannot open shared object file: No such file or directory

Follow the answer here: https://stackoverflow.com/questions/20842732/libpython2-7-so-1-0-cannot-open-shared-object-file-no-such-file-or-directory

Try to find file libpython2.7.so.1.0:
locate libpython2.7.so.1.0
In my case, it show out put:
	/opt/rh/python27/root/usr/lib64/libpython2.7.so.1.0
Then paste line /opt/rh/python27/root/usr/lib64 to file /etc/ld.so.conf
And run ldconfig