title: how install python3.4 psycopg2 in centos pyvenv
body: <p>i install python 3.4 in my centos 6.5
  i follow this tutorial </p>
  
  <p><a href="http://toomuchdata.com/2014/02/16/how-to-install-python-on-centos/" rel="nofollow">http://toomuchdata.com/2014/02/16/how-to-install-python-on-centos/</a></p>
  
  <p>so i do not change the system defaule python 2.6.6</p>
  
  <p>and i use python3.4 pyvenv create a project folder for my django website
  now i need install postgresql database,so i try install psycopg2.
  in that pyvenv ,the python version is 3.4 </p>
  
  <p>when i pip install psycopg2,it show the error</p>
  
  <pre><code>Downloading psycopg2-2.5.2.tar.gz (685kB): 685kB downloaded
    Running setup.py (path:/mysns/build/psycopg2/setup.py) egg_info for package psycopg2
  
      Error: pg_config executable not found.
  
      Please add the directory containing pg_config to the PATH
      or specify the full executable path with the option:
  
          python setup.py build_ext --pg-config /path/to/pg_config build ...
  
      or with the pg_config option in 'setup.cfg'.
      Complete output from command python setup.py egg_info:
      running egg_info
  
  creating pip-egg-info/psycopg2.egg-info
  
  writing pip-egg-info/psycopg2.egg-info/PKG-INFO
  
  writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
  
  writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
  
  writing manifest file 'pip-egg-info/psycopg2.egg-info/SOURCES.txt'
  
  warning: manifest_maker: standard file '-c' not found
  
  
  
  Error: pg_config executable not found.
  
  
  
  Please add the directory containing pg_config to the PATH
  
  or specify the full executable path with the option:
  
  
  
      python setup.py build_ext --pg-config /path/to/pg_config build ...
  
  
  
  or with the pg_config option in 'setup.cfg'.
  
  ----------------------------------------
  Cleaning up...
  Command python setup.py egg_info failed with error code 1 in /mysns/build/psycopg2
  Storing debug log for failure in /root/.pip/pip.log
  </code></pre>
  
  <p>then i do a little search ,someone say i need install other lib
  i need do this </p>
  
  <p>yum install libpqxx-devel python-devel</p>
  
  <p>every thing install complete
   however ,then i install psycopg2,
  pip install psycopg2,
  it still show the same error
  then i notice ,the previous lib ,only intall python-devel-2.6.6 
  this is the default system python version
  even i try</p>
  
  <p>yum python3-devel,</p>
  
  <p>it do not install python3.4 devel lib to my python3.4 pyvenv folder</p>
  
  <p>how can i fix the problem? can i install python3.4 devel lib in this pyvenv folder?</p>