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 ...
Note: Since a while back, there are binary wheels for Windows in PyPI, so this should no longer be an issue for Windows users. Below are solutions for Linux, Mac users, since lots of them find this post through web searches.
Option 1
Install the psycopg2-binary PyPI package instead, it has Python wheels for Linux and Mac OS.
pip install psycopg2-binary
Option 2
Install the prerequsisites for building the psycopg2 package from source:
Debian/Ubuntu
Python 3
sudo apt install libpq-dev python3-dev
You might need to install python3.8-dev or similar for e.g. Python 3.8.
Python 2
sudo apt install libpq-dev python-dev
If that's not enough, try
sudo apt install build-essential
or
sudo apt install postgresql-server-dev-all
as well before installing psycopg2 again.
CentOS 6
See Banjer's answer
macOS
See nichochar's answer
On CentOS, you need the postgres dev packages:
sudo yum install python-devel postgresql-devel
That was the solution on CentOS 6 at least.
If you're on a mac you can use homebrew
brew install postgresql
And all other options are here: http://www.postgresql.org/download/macosx/
On Mac Mavericks with Postgres.app version 9.3.2.0 RC2 I needed to use the following code after installing Postgres:
sudo PATH=$PATH:/Applications/Postgres.app/Contents/Versions/9.3/bin pip install psycopg2
I recently configured psycopg2 on a windows machine. The easiest install is using a windows executable binary. You can find it at http://stickpeople.com/projects/python/win-psycopg/.
To install the native binary in a virtual envrionment, use easy_install:
C:\virtualenv\Scripts\> activate.bat
(virtualenv) C:\virtualenv\Scripts\> easy_install psycopg2-2.5.win32-py2.7-pg9.2.4-release.exe
For Python 3 you should use sudo apt-get install libpq-dev python3-dev under Debian.
This is what worked for me (On RHEL, CentOS:
sudo yum install postgresql postgresql-devel python-devel
And now include the path to your postgresql binary dir with you pip install:
sudo PATH=$PATH:/usr/pgsql-9.3/bin/ pip install psycopg2
Make sure to include the correct path. Thats all :)
UPDATE: For python 3, please install python3-devel instead of python-devel
The answers so far are too much like magic recipes. The error that you received tells you that pip cannot find a needed part of the PostgreSQL Query library. Possibly this is because you have it installed in a non-standard place for your OS which is why the message suggests using the --pg-config option.
But a more common reason is that you don't have libpq installed at all. This commonly happens on machines where you do NOT have PostgreSQL server installed because you only want to run client apps, not the server itself. Each OS/distro is different, for instance on Debian/Ubuntu you need to install libpq-dev. This allows you to compile and link code against the PostgreSQL Query library.
Most of the answers also suggest installing a Python dev library. Be careful. If you are only using the default Python installed by your distro, that will work, but if you have a newer version, it could cause problems. If you have built Python on this machine then you already have the dev libraries needed for compiling C/C++ libraries to interface with Python. As long as you are using the correct pip version, the one installed in the same bin folder as the python binary, then you are all set. No need to install the old version.
If you using Mac OS, you should install PostgreSQL from source.
After installation is finished, you need to add this path using:
export PATH=/local/pgsql/bin:$PATH
or you can append the path like this:
export PATH=.../:usr/local/pgsql/bin
in your .profile file or .zshrc file.
This maybe vary by operating system.
You can follow the installation process from http://www.thegeekstuff.com/2009/04/linux-postgresql-install-and-configure-from-source/
On Debian/Ubuntu:
First install and build dependencies of psycopg2 package:
# apt-get build-dep python-psycopg2
Then in your virtual environment, compile and install psycopg2 module:
(env)$ pip install psycopg2
Run below commands and you should be fine
$ apt-get update
$ apt install python3-dev libpq-dev
$ pip3 install psycopg2
I've done this before where in windows you install first into your base python installation.
Then, you manually copy the installed psycopg2 to the virtualenv install.
It's not pretty, but it works.
Before you can install psycopg2 you will need to install the python-dev package.
If you're working from Linux (and possibly other systems but i can't speak from experience) you will need to make sure to be quite exact about what version of python your running when installing the dev package.
For example when I used the command:
sudo apt-get install python3-dev
I still ran into the same error when trying to
pip install psycopg2
As I am using python 3.7 I needed to use the command
sudo apt-get install python3.7-dev
Once I did this I ran into no more issues. Obviously if your on python version 3.5 you would change that 7 to a 5.
Besides installing the required packages, I also needed to manually add PostgreSQL bin directory to PATH.
$vi ~/.bash_profile
Add PATH=/usr/pgsql-9.2/bin:$PATH before export PATH.
$source ~/.bash_profile
$pip install psycopg2
For MacOS,
Use the below command to install psycopg2, works like charm!!!
env LDFLAGS="-I/usr/local/opt/openssl/include -L/usr/local/opt/openssl/lib" pip install psycopg2
On windows XP you get this error if postgres is not installed ...
I installed Postgresql92 using the RedHat / CentOS repository on PG's downloads site http://www.postgresql.org/download/linux/redhat/
To get pg_config, I had to add /usr/pgsql-9.2/bin to PATH.
On Fedora 24: For Python 3.x
sudo dnf install postgresql-devel python3-devel
sudo dnf install redhat-rpm-config
Activate your Virtual Environment:
pip install psycopg2
Psycopg2 Depends on Postgres Libraries.
On Ubuntu You can use:
apt-get install libpq-dev
Then:
pip install psycopg2
I've been battling with this for days, and have finally figured out how to get the "pip install psycopg2" command to run in a virtualenv in Windows (running Cygwin).
I was hitting the "pg_config executable not found." error, but I had already downloaded and installed postgres in Windows. It installed in Cygwin as well; running "which pg_config" in Cygwin gave "/usr/bin/pg_config", and running "pg_config" gave sane output -- however the version installed with Cygwin is:
VERSION = PostgreSQL 8.2.11
This won't work with the current version of psycopg2, which appears to require at least 9.1. When I added "c:\Program Files\PostgreSQL\9.2\bin" to my Windows path, the Cygwin pip installer was able to find the correct version of PostgreSQL, and I was able to successfully install the module using pip. (This is probably preferable to using the Cygwin version of PostgreSQL anyway, as the native version will run much quicker).
On OpenSUSE 13.2, this fixed it:
sudo zypper in postgresql-devel
For lowly Windows users were stuck having to install psycopg2 from the link below, just install it to whatever Python installation you have setup. It will place the folder named "psycopg2" in the site-packages folder of your python installation.
After that, just copy that folder to the site-packages directory of your virtualenv and you will have no problems.
here is the link you can find the executable to install psycopg2
http://www.lfd.uci.edu/~gohlke/pythonlibs/
On Ubuntu I just needed the postgres dev package:
sudo apt-get install postgresql-server-dev-all
*Tested in a virtualenv
I could install it in a windows machine and using Anaconda/Spyder with python 2.7 through the following commands:
!pip install psycopg2
Then to establish the connection to the database:
import psycopg2
conn = psycopg2.connect(dbname='dbname',host='host_name',port='port_number', user='user_name', password='password')
In Arch base distributions:
sudo pacman -S python-psycopg2
pip2 install psycopg2 # Use pip or pip3 to python3
On OSX 10.11.6 (El Capitan)
brew install postgresql
PATH=$PATH:/Library/PostgreSQL/9.4/bin pip install psycopg2
On OSX with macports:
sudo port install postgresql96
export PATH=/opt/local/lib/postgresql96/bin:$PATH
if pip is not working than you can download .whl file from here https://pypi.python.org/pypi/psycopg2
extract it..
than python setup.py install
I was having this problem, the main reason was with 2 equal versions installed. One by postgres.app and one by HomeBrew.
If you choose to keep only the APP:
brew unlink postgresql
pip3 install psycopg2
Installation on MacOS
Following are the steps, which worked for me and my team members while installing psycopg2 on Mac OS Big Sur and which we have extensively tested for Big Sur. Before starting make sure you have the Xcode command-line tool installed. If not, then install it from the Apple Developer site. The below steps assume you have homebrew installed. If you have not installed homebrew then install it. Last but not the least, it also assumes you already have PostgreSQL installed in your system, if not then install it. Different people have different preferences but the default installation method on the official PostgreSQL site via Enterprise DB installer is the best method for the majority of people.
Put up the linkage to pg_config file in your .zshrc file by: export PATH="$PATH:/Library/PostgreSQL/12/bin:$PATH". This way you are having linkage with the pg_config file in the /Library/PostgreSQL/12/bin folder. So if your PostgreSQL installation is via other means, like Postgres.app or Postgres installation via homebrew, then you need to have in your .zshrc file the link to pg_config file from the bin folder of that PostgreSQL installation as psycopg2 relies on that.
Install OpenSSL via Homebrew using the command brew install openssl. The reason for this is that libpq, the library which is the basis of psycopg2, uses openssl - psycopg2 doesn't use it directly. After installing put the following commands in your .zshrc file:
export PATH="/usr/local/opt/openssl#1.1/bin:$PATH"
export LDFLAGS="-L/usr/local/opt/openssl#1.1/lib"
export CPPFLAGS="-I/usr/local/opt/openssl#1.1/include"
By doing this you are creating necessary linkages in your directory. These commands are suggested by brew while you install openssl and have been directly picked up from there.
Now comes the most important step, which is to install libpq using the command brew install libpq. This installs libpq library. As per the documentation
libpq is the C application programmer's interface to PostgreSQL. libpq is a set of library functions that allow client programs to pass queries to the PostgreSQL backend server and to receive the results of these queries.
Link libpq using brew link libpq, if this doesn't work then use the command: brew link libpq --force.
Also put in your .zshrc file the following export PATH="/usr/local/opt/libpq/bin:$PATH". This creates all the necessary linkages for libpq library .
Now restart the terminal or use the following command source ~/.zshrc.
This works even when you are working in conda environment.
N.B. pip install psycopg2-binaryshould be avoided because as per the developers of the psycopg2 library
The use of the -binary packages in production is discouraged because in the past they proved unreliable in multithread environments. This might have been fixed in more recent versions but I have never managed to reproduce the failure.
I'm having a ROS-node that uses Python 3.5 and I want to run it on ROS-Kinetic. This is supposed to run on Ubuntu 16.04 with Kernel 4.4.
I've read that it's complicated to match ROS-Kinetic with Python 3 because it's not officially supported...but I've also read that it is possible to do so...
There are several installation guides for specific packages and I've tried some of them but failed everytime.
What I've tried so far:
1) Installed ROS-Kinetic-desktop-full
2) pip3 install rospkg catkin_pkg
3) export PYTHONPATH = /usr/local/lib/python3.5/dist-packages
When I'm running catkin_make, the first error appearing says:
... ImportError: No module named genmsg ...
Can anyone please write an exact installation guide for making ROS-Kinetic run with Python 3.5 (without a virtual environment) or tell me what's missing in my installation?
Thanks in advance!
An alternative to Some progammer's answer, you could install the packages in global space
sudo apt-get install python3-yaml # you'll also need this
sudo pip3 install rospkg catkin_pkg
or add --user flag
pip3 install --user rospkg catkin_pkg
People used Python 3.5 + ROS-Kinetic in Ubuntu before (for example, check out cozmo_driver) and it should work according to REP3.
You are not exporting the right folder to PYTHONPATH. Try
export PYTHONPATH=/opt/ros/kinetic/lib/python2.7/dist-packages/
I'm having a little trouble with virtualenv on Mac OS X Yosemite. After I couldn't run virtualenv at all first, I installed Python 3 via brew (previously I installed it via the package on python.org). I linked this installation of python3, updated pip and ran pip3 install virtualenv. When I try to run virtualenv (e.g. $ virtualenv --python=python3 ../virtualenv), I get the following error message.
Traceback (most recent call last):
File "/usr/local/bin/virtualenv", line 7, in <module>
from virtualenv import main
File "/usr/local/bin/virtualenv.py", line 7, in <module>
from virtualenv import main
ImportError: cannot import name 'main'
Can anybody help me with this?
After my upgrade to Fedora 32 I had the same issue which lead me to this question:
ImportError: cannot import name 'main' from 'virtualenv'
In my case I actually seemed to have both /usr/local/bin/virtualenv as well as $HOME/.local/lib/python3.8/site-packages/virtualenv/__init__.py.
Removing the user virtualenv version and reinstalling it into the system with root fixed the issue:
pip uninstall virtualenv
sudo pip install virtualenv
Your virtualenv executable /usr/local/bin/virtualenv is importing the virtualenv package /usr/local/bin/virtualenv.py. My guess is that package is not the one the executable should really be importing. The reason it is choosing that one is because it is in the same directory.
First, check where the real virtualenv package is. In the python3 terminal:
>>> import virtualenv
>>> virtualenv.__file__
If it is not /usr/local/bin/virtualenv.py, then the simplest way to get /usr/local/bin/virtualenv to import it instead of /usr/local/bin/virtualenv.py is to delete /usr/local/bin/virtualenv.py (or so you can easily undo this if it doesn't work, simply rename virtualenv.py to something else like xvirtualenvx.py).
I received this error after upgrading Ubuntu 18.04 LTS to 20.04 LTS. So there were two problems all at once. First the python version was still running 2.x and doing a simple update or try to uninstall (apt-get remove virtualenv) of virtualenv did not help at all. But I found a solution. First let 20.04 LTS 'know' the times of using old python is over:
sudo apt-get install python-is-python3
Then test it and open a console to get the version string with python -V; by now it should be showing something like Python 3.8.5. Fine.
Next step is to solve the virtualenv problem. I tried to find out, which executable was run with which virtualenv and it showed: $HOME/.local/bin/virtualenv. Hmmkay, somehow the system wasn't using the /usr/bin/virtualenv executable. I thought maybe I let the directory become invisible (a.k.a. renaming) and maybe the system will go on a hunt for an alternative virtualenv running:
mv $HOME/.local/bin/virtualenv /home/USER/.local/bin/virtualenv_OLD
Then I simply changed into a playground-directory and ran virtualenv donaldknuth and behold - it worked. To be sure I ran another which virtualenv and the system returned a /usr/bin/virtualenv. Last check to do was activating the new virtual environment:
source $HOME/playground/donaldknuth/bin/activate
The terminal changed and it worked fine. Solution
EDIT:
Based on Pierre B.'s suggestion you may have to restart your Shell. The command hash -d virtualenv will delete the stored location of virtualenv from the shell's cache and determine the correct path right now. (Sources: https://www.computerhope.com/unix/bash/hash.htm, https://unix.stackexchange.com/questions/5609/how-do-i-clear-bashs-cache-of-paths-to-executables)
Similarly to some others here, I had multiple installations of virtualenv. Not sure where the extra one came from, but I had these two:
/usr/local/bin/virtualenv
/usr/bin/virtualenv
One is from apt install of virtualenv, the other from pip install of virtualenv.
This happened when upgrading to Ubuntu 20.04.
On Linux Mint 20, I had to switch default Python interpreter to python3
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 1
Then remove existing virtualenv and reinstall via pip and python3:
rm ~/.local/bin/virtualenv
apt remove python3-virtualenv
sudo pip install virtualenv