Downloading/unpacking psycopg2
Downloading psycopg2-2.5.4.tar.gz (682kB): 682kB downloaded
Running setup.py (path:/home/ql/.pyenv/versions/py2/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 /home/ql/.pyenv/versions/py2/build/psycopg2
Storing debug log for failure in /tmp/tmpDCTXLA

下面是我在网上看到的解决方式
1.将pg_config添加进环境变量
PATH=$PATH:/usr/pgsql-9.1/bin/
2.安装libpq-dev python-dev
sudo yum install libpq-dev python-dev
3.安装build-dep python-psycopg2
sudo yum install build-dep python-psycopg2
4.安装postgresql-devel
sudo yum install postgresql-devel*

据广大网友所说，python-dev在centos上为python-devel
于是我最终成功安装了python-devel python-psycopg2 python-devel，
最终也确实解决了问题，把这些包一股脑全装上就完事了，每次碰到这种问题
都是说升级pip的，但是没一次有效。。