On Centos6.6(Final) I want to install a newer version of python:
# wget http://www.python.org/ftp/python/2.7.7/Python-2.7.7.tgz
# tar xvzf Python-2.7.7.tgz
# cd Python-2.7.7
# ./configure
# make
# make altinstall

It installed with no errors. I added the python2.7 path to PYTHONPATH and PATH. When I run the new version:

[Python-2.7.7]$ python2.7
Python 2.7.7 (default, Mar 2 2015, 16:59:59)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-11)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
Traceback (most recent call last):
File "/home/acameron/.pystartup", line 13, in <module>
import readline
ImportError: No module named readline
>>>

Do I need additional path information? What about the site-packages?

Thanks,
ANDY

The error is generated by 'import readline' line in file '/home/acameron/.pystartup' python startup file. Please try renaming that file to something else temporarily.

Then try running the python2.7.

You have to figure out to remedy the problem.

The error means python can't locate the module readline provided by readline command line editing package.

While building python try running ./configure --help to see if there is an option for --with-readline and if present rebuild with that option.

Moving the file simply generates an error at python2.7 startup

Could not open PYTHONSTARTUP
IOError: [Errno 2] No such file or directory: '/home/acameron/.pystartup'

The python2.7 starts OK even with the error. If I remove PYTHONSTARTUP from the environment variable list, I will have no python history function. Also the other version of python (python2.6) starts without the error.

Thanks,
ANDY

have you ran
then linking the programs that NEED the newer python to that one