How to install psycopg2 with "pip" on Python?

ghz 3months ago ⋅ 60 views

I'm using virtualenv and I need to install "psycopg2".

I have done the following:

pip install http://pypi.python.org/packages/source/p/psycopg2/psycopg2-2.4.tar.gz#md5=24f4368e2cfdc1a2b03282ddda814160

And I have the following messages:

Downloading/unpacking http://pypi.python.org/packages/source/p/psycopg2/psycopg2
-2.4.tar.gz#md5=24f4368e2cfdc1a2b03282ddda814160
  Downloading psycopg2-2.4.tar.gz (607Kb): 607Kb downloaded
  Running setup.py egg_info for package from http://pypi.python.org/packages/sou
rce/p/psycopg2/psycopg2-2.4.tar.gz#md5=24f4368e2cfdc1a2b03282ddda814160
    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'.

----------------------------------------
Command python setup.py egg_info failed with error code 1
Storing complete log in C:\Documents and Settings\anlopes\Application Data\pip\p
ip.log

My question, I only need to do this to get the psycopg2 working?

python setup.py build_ext --pg-config /path/to/pg_config build ...

Answers

The error you're encountering happens because psycopg2 requires PostgreSQL development libraries and header files to compile, specifically the pg_config utility, which is part of the PostgreSQL client installation. Without pg_config, the installation can't proceed because it needs this utility to locate PostgreSQL headers and libraries.

Here are the steps to resolve the issue:

1. Install PostgreSQL Development Libraries

You need to install the PostgreSQL development libraries for your system. This will provide the pg_config utility that psycopg2 requires.

On Ubuntu/Debian:

sudo apt-get install libpq-dev python-dev

On Fedora/RHEL:

sudo yum install postgresql-devel python-devel

On macOS:

If you have PostgreSQL installed through brew:

brew install postgresql

Alternatively, you can download and install the full PostgreSQL package from the PostgreSQL website.

On Windows:

If you're using Windows, it's trickier to compile psycopg2 from source due to the PostgreSQL development libraries requirement. You can either:

  • Install the pre-compiled binary version: This is the easiest approach, as it avoids the need for PostgreSQL headers. You can download pre-compiled binary versions of psycopg2 for Windows from here.
  • Install PostgreSQL: You can install PostgreSQL using the PostgreSQL installer for Windows. Ensure the pg_config utility is on your PATH.

2. Ensure pg_config is in Your PATH

After installing PostgreSQL, ensure that the pg_config utility is in your PATH. To check if it's available, you can run:

pg_config --version

If it returns a version number, you’re good to go. If not, locate the pg_config binary (usually in /usr/pgsql-xx/bin/pg_config or /usr/local/bin/pg_config on Linux or in the PostgreSQL installation directory on macOS or Windows) and add it to your PATH.

For example:

export PATH=$PATH:/path/to/pg_config_directory

3. Install psycopg2

Once pg_config is available, retry installing psycopg2:

pip install psycopg2

If you don't need to compile psycopg2 from source (and especially if you're on Windows), you can install a binary version that doesn’t require pg_config or development headers:

pip install psycopg2-binary

Note: The psycopg2-binary package is a self-contained package and is suitable for most applications, though it's recommended to switch to the compiled version (psycopg2) in production for better performance and stability.

Summary

  1. Install the PostgreSQL development libraries (libpq-dev, postgresql-devel, etc.).
  2. Ensure pg_config is available in your PATH.
  3. Install psycopg2 via pip or use psycopg2-binary if you're on Windows or don’t need to compile from source.

This should resolve the issue, and you'll be able to install psycopg2 successfully.

#py