Thread: Trouble installing psycopg2

On Thu, Sep 26, 2013 at 01:01:54PM -0400, Laura Tateosian wrote:
- Hi,  I'm trying to install psycopg2 on a Centos 5, 64-bit machine.   I have
- both 2.4 and 2.7 Python versions on this machine.  I attempted to install
- using
- easy-install2.7 psycopg2
-
- The install is not working.  (I can't import psycopg2 in a python 2.7
- session).   yum doesn't list it as installed.  But when I try to install it
- again, easy_install responds that it's already installed.  That's the short
- version of the problem, more details below that may or may not be helpful.
-
- Thanks,
- LT
-
-
-
-
- At first, easy-install2.7 psycopg2 gave me similar errors to what's
- described on this page:
- http://stackoverflow.com/questions/9600111/install-pg-config-in-centos-5-5-without-yum(something
- to do with pg_config not found).  So I followed the advice of
- installing devel
-
- yum install postgresql84-devel
-
- ...succeeded.
-
- Then, I  "easy-install2.7 psycopg2" again.  In fact I piped the output to a
- file and got what I have below, but it also flashed up an error message
- which didn't get into this file and I can't see on the history.  But from
- that second  that I saw it, I know it had __FILE__ in it.   Now I'm in this
- installed/but not installed kind of limbo.
- ...
- Excluding Packages in global exclude list
- Finished
- Available Packages
- python-psycopg2.x86_64                      2.0.14-2.el5
- epel
- python-psycopg2-doc.x86_64                  2.0.14-2.el5
- epel
- python-psycopg2-zope.x86_64                 2.0.14-2.el5
- epel
- root@server [/opt/bin]# easy_install-2.7 psycopg2
- Searching for psycopg2
- Searching for psycopg2
- Reading http://pypi.python.org/simple/psycopg2/
- Reading http://initd.org/projects/psycopg2
- Best match: psycopg2 2.5.1
- Downloading
- https://pypi.python.org/packages/source/p/psycopg2/psycopg2-2.5.1
- .tar.gz#md5=1b433f83d50d1bc61e09026e906d84c7
- Processing psycopg2-2.5.1.tar.gz
- Writing /tmp/easy_install-UYNn1g/psycopg2-2.5.1/setup.cfg
- Running psycopg2-2.5.1/setup.py -q bdist_egg --dist-dir
- /tmp/easy_install-UYN
- n1g/psycopg2-2.5.1/egg-dist-tmp-FLKSTs
- Adding psycopg2 2.5.1 to easy-install.pth file
-
- Installed
- /usr/local/lib/python2.7/site-packages/psycopg2-2.5.1-py2.7-linux-x
- 86_64.egg
- Processing dependencies for psycopg2
- Finished processing dependencies for psycopg2


So easy_install isn't going to intall the yum version, and it may install it somewhere
that the system python isn't looking for it.

That's generally why you  don't want to use easy_install or pip if you can avoid it.
If you DO use them you should use virtualenv and virtualenvwrapper.

Since you have an OS package, Your best bet is to do 'yum install python-psycopg2'
and see if that works for you.

On Thu, Sep 26, 2013 at 02:56:14PM -0400, Augori wrote:
- Thanks, for the replies Chris and David.
-
- Chris, I couldn't find any psycopg files under my Python installs, so I
- decided to try David's advice and yum install python-psycopg2
- It reported success, but it installed it under
- ../usr/lib64/python2.4/site-packages
-
- I'm working with Python2.7.5, so psycopg2 won't import.   It believe that
- psycopg2 is not written for 2.4 or below.  That's why I installed 2.7.5.
- So my question now is, how can I get yum to install it in the 2.7
- site-packages?
-
- Thanks.
-
- PS.  About the virtualenv suggestion, I had tried using use virtualenv and
- virtualenvwrapper, following the instructions on this nice site.
- http://bda.ath.cx/blog/2009/04/08/installing-python-26-in-centos-5-or-rhel5/
- But, I couldn't get the bashrc to run without error, after adding this
- update
-
- source /opt/bin/virtualenvwrapper_bashrc
-
- So, I thought I'd throw caution to the wind and skip that part.
- (that's how I got to easy_intall, which at least allowed me to specify
- which python version)

Looking at the easy_install on my system it uses python26
head -1 /usr/bin/easy_install
#!/usr/bin/python2.6

so if you use easy_install you probably just installed it to the 2.6 stuff.

If you need 2.7 for your stuff then you'll definitely want to get virtualenv
working. If you can live with 2.6 then get rid of 2.7 on your machine
and work with the yum packages.

A better virtualenvwrapper setup doc is here (not from 2009)
http://virtualenvwrapper.readthedocs.org/en/latest/

On 09/26/2013 11:56 AM, Augori wrote:
> Thanks, for the replies Chris and David.
>
> Chris, I couldn't find any psycopg files under my Python installs, so I
> decided to try David's advice and yum install python-psycopg2
> It reported success, but it installed it under
> ../usr/lib64/python2.4/site-packages

The easy_install version was not under?:

/usr/local/lib/python2.7/site-packages/


--
Adrian Klaver
adrian.klaver@gmail.com

On 09/26/2013 02:14 PM, Augori wrote:
> Okay, I'm sorry for the questions.  But I'm really confused about where
> things are being installed.  I know that yum installed it under 2.4
> site-packages because I checked for it inside there before and after I
> ran the yum command.
>
> There is an easy_install.pth file under /usr/local/lib/python2.7/site-
> packages/ as well, but would that be invoked when I call easy_install
> when I'm logged in as root?
>
> As for 2.6, that would be fine, but I don't seem to have a
> /user/bin/python2.6 (whereas, I do have a  /user/bin/python2.4). Maybe
> it's because I'm on CentOS5, which comes with 2.4.
>
> I tried to use the rpm --prefix flag to move the rpm, but to no avail.
>

Well you said you have both Python 2.4 and 2.7 installed on the machine.

Were they both installed via Centos package management?

If so Python 2.4 is probably set as the default and if you install the
package for Python it will install for 2.4. You probably need to specify
the python version. Not sure how Centos names its packages, but I am
using openSUSE and the default package(where the default Python is 2.7)
is python-psycopg2 and the Python 3 version(which I also have installed)
is python3-psycopg2


--
Adrian Klaver
adrian.klaver@gmail.com

On 9/26/2013 7:07 PM, Augori wrote:
> I think you're right about Python2.4 being set as the default.  Does
> anyone know how to persuade it otherwise for installation purposes?
>

path.

absolutely do NOT replace the OS distribution python unless you want to
break lots of stuff (for instance, yum on rhel/centos is written in python)



--
john r pierce                                      37N 122W
somewhere on the middle of the left coast

On 09/26/2013 07:07 PM, Augori wrote:
> I think Python 2.4 was installed with the OS.  I installed Python 2.7
> from an .egg file that I downloaded.  I'm  a bit new to this
> terminology, so not sure if that considered Centos package management.

No.

>
> I think you're right about Python2.4 being set as the default.  Does
> anyone know how to persuade it otherwise for installation purposes?

Well it seems you already have psycopg2 installed for Python 2.7, it
just cannot find it. Here is a possible solution.

Open the Python 2.7 shell

import sys

then

sys.path

This will show a list of paths that Python 2.7 knows about. Look to see
if /usr/local/lib/python2.7/site-packages/ is listed.

If not, you can temporarily include it by doing:

sys.path.append('/usr/local/lib/python2.7/site-packages/')

and then

import psycopg2

If it is indeed installed in /usr/local/lib/python2.7/site-packages/ it
should load.

To make the change 'permanent' create a  *.pth file in one of the
directories shown when you first did sys.path, preferably a
site-packages one. In the file  put
'/usr/local/lib/python2.7/site-packages/ . Then name the file, say
usr_local.pth. Python adds directories in *.pth files to the sys.path.

> Thanks.
>


--
Adrian Klaver
adrian.klaver@gmail.com

On 09/27/2013 04:45 AM, Augori wrote:
> *Thanks again for the suggestions.  It doesn't look to me like it's
> installed in /usr/local/lib/python2.7/site-packages.  There's an egg
> directory there, but otherwise, no psycopg2.  The egg directory doesn't
> mean it's installed, does it?? Here's an ls of that site-packages dir:*
>

Yes, an egg is just a zip file that at the destination may remain zipped
or be unzipped into a directory:

http://stackoverflow.com/questions/2051192/what-is-a-python-egg

>
> *If I modify my sys.path, it still doesn't import psycopg2. The python
> command runs version 2.7.5 and you can see that in evidence in the sys
> path. It is looking at a different Python 2.7 that I installed under
> opt/bin and added to the PATH variable when I was trying to set up a
> virtualenvwrapper. *

So you have two versions of Python 2.7 in play, this complicates the issue.

>

> *But I can't get psycopg2 to install to the 2.7.5 directory.  Its
> site-packages is completely empty:*
>
> root@server [/usr/bin]# ls /opt/lib/python2.7/site-packages
> ./  ../  README

Probably because programs are being installed in the other version of
Python 2.7

>
>
> *whereas, /usr/lib64/python2.4/site-packages/ is full of stuff,
> including psycopg2.  I've pasted just a small portion of the ls results
> below.*

It is the default Python and the one CentOS is using when it
installs/updates Python.

>
> *I also tried appending this path and importing.  That gives a different
> error --tries to import it but fails, probably because it's inside a 2.4
> install:*
>

That is correct Python 2.7 needs a version of psycopg2 compiled for it
not 2.4.

>
> Do you have other ideas?

Clean house. Uninstall the two versions of Python 2.7 you have and start
over.

A bit of Googling found the below, it refers to CentOS 6 but is pointed
to by people as useful on CentOS 5 also.

http://toomuchdata.com/2012/06/25/how-to-install-python-2-7-3-on-centos-6-2/

--
Adrian Klaver
adrian.klaver@gmail.com

On 09/27/2013 04:45 AM, Augori wrote:

>
> Do you have other ideas?
>

Re: my previous post. I was assuming you are not using Python 2.7 for
anything important at this point. That might be an erroneous assumption,
in which case truly cleaning house might not be the way to go.


--
Adrian Klaver
adrian.klaver@gmail.com

On 09/29/2013 09:38 AM, Augori wrote:
> Thanks to Adrian for pointing to this site.
> http://toomuchdata.com/2012/06/25/how-to-install-python-2-7-3-on-centos-6-2/
>   I was able to get the virtual environment set up and install psycopg2
> from there.  Now things seem to be working well when I'm logged in as root.
>
> But I need to be able to use the virtualenv as a non-root user, joshmoe.
>   (And start/stop postgresql as this other user)

> I've found a good many examples of sudoer statements.  But I can't
> figure out the syntax that will make this work.  I'm hoping once I get
> this one, I'll be able to give access to statements like 'service
> postgresql status' and so forth.


Looks to me you installed the virtualenv as user root into /root. Why
not install the virtualenv as joshme into /joshme? Then you avoid the
sudo problems all together. It also one of the benefits of virtualenv
you can run programs as an ordinary user and not make them system wide.


--
Adrian Klaver
adrian.klaver@gmail.com

On 09/29/2013 11:06 AM, Augori wrote:
> Hmm maybe you're right.  I just tried starting over again from a
> directory under joshmoe, following the tutorial again, but I get
> permssions errors at every turn.
>
> # wgethttp://python.org/ftp/python/2.7.3/Python-2.7.3.tar.bz2
> # tar xf Python-2.7.3.tar.bz2
> # cd Python-2.7.3
> # ./configure --prefix=/usr/local
> # make && makealtinstall
>



>
> Since it's already their, I thought maybe I could skip to these steps
> but they give permission errors as well
>
> # wgethttp://pypi.python.org/packages/source/d/distribute/distribute-0.6.35.tar.gz
> # tar xf distribute-0.6.35.tar.gz
> # cd distribute-0.6.35
> # python2.7 setup.py install
>
> I guess this is the reason I started installing things from root.
>


The above steps should be run as root preferably via sudo. You have
already done that as well as the step that installed virtualenv. My
suggestion was to run the below as joshmoe in joshmoes home directory:

virtualenv-2.7 --distribute someproject

source someproject/bin/activate
(someproject)# python --version

Then install psycopg2 in that virtualenv.

This assumes you want to run psycopg2 in a virtualenv. I am not sure
what the end point of all this i.e. how you want to use psycopg2?


--
Adrian Klaver
adrian.klaver@gmail.com