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I'm getting an error Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed? when trying to install lxml through pip.
c:\users\f\appdata\local\temp\xmlXPathInitqjzysz.c(1) : fatal error C1083: Cannot open include file: 'libxml/xpath.h': No such file or directory
*********************************************************************************
Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?
*********************************************************************************
error: command 'C:\\Users\\f\\AppData\\Local\\Programs\\Common\\Microsoft\\Visual C++ for Python\\9.0\\VC\\Bin\\cl.exe' failed with exit status 2
I don't find any libxml2 dev packages to install via pip.
Using Python 2.7 and Python 3.x on x86 in a virtualenv under Windows 10.
Install lxml from http://www.lfd.uci.edu/~gohlke/pythonlibs/#lxml for your python version. It's a precompiled WHL with required modules/dependencies.
The site lists several packages, when e.g. using Win32 Python 3.11, use lxml‑4.9.0‑cp311‑cp311‑win32.whl.
Download the file, and then install with:
pip install C:\path\to\downloaded\file\lxml‑4.9.0‑cp311‑cp311‑win32.whl
I had this issue and realised that whilst I did have libxml2 installed, I didn't have the necessary development libraries required by the python package. Installing them solved the problem:
sudo apt-get install libxml2-dev libxslt1-dev
sudo pip install lxml
Try to use:
easy_install lxml
That works for me, win10, python 2.7.
On Mac OS X El Capitan I had to run these two commands to fix this error:
xcode-select --install
pip install lxml
Which ended up installing lxml-3.5.0
When you run the xcode-select command you may have to sign a EULA (so have an X-Term handy for the UI if you're doing this on a headless machine).
In case anyone else has the same issue as this on
Centos, try:
yum install python-lxml
Ubuntu
sudo apt-get install -y python-lxml
worked for me.
set STATICBUILD=true && pip install lxml
run this command instead, must have VS C++ compiler installed first
https://blogs.msdn.microsoft.com/pythonengineering/2016/04/11/unable-to-find-vcvarsall-bat/
It works for me with Python 3.5.2 and Windows 7
I tried install a lib that depends lxml and nothing works. I see a message when build was started: "Building without Cython", so after install cython with apt-get install cython, lxml was installed.
I had this issue and realized that while I did have libxml2 installed, I didn't have the necessary development libraries required by the python package.
1) Installing them solved the problem:
The site to download the file: Download
2) After Installing the file save it in a accessible folder
pip install *path to that file*
For some reason it doesn't work in python 3.11, but 3.10 works.
On windows, to install a module with a previous version, use
py -3.10 -m pip install lxml
if you want to install it in a venv, then use
py -3.10 -m venv .venv
.venv/Scripts/pip.exe install lxml
if you've set up the venv, then you can just use
pip install lxml
You also need to run the python program with that version. If you set up a venv, then you don't need to do this.
py -3.10 file.py
It is not strange for me that none of the solutions above came up, but I saw how the igd installation removed the new version and installed the old one, for the solution I downloaded this archive:https://pypi.org/project/igd/#files
and changed the recommended version of the new version: 'lxml==4.3.0' in setup.py
It works!
I got the same error for python 32 bit. After install 64bit, the problem was fixed.
I am using venv.
In my case it was enough to add lxml==4.6.3 to requirements.txt.
One library wanted earlier version and this was causing this error, so when I forced pip to use newest version (currently 4.6.3) installation was successful.
I run pyinstaller test.py and got a following error.
OSError: Python library not found: Python3, Python, libpython3.9.dylib, libpython3.9m.dylib, .Python
This would mean your Python installation doesn't come with proper library files.
This usually happens by missing development package, or unsuitable build parameters of Python installation.
* On Debian/Ubuntu, you would need to install Python development packages
* apt-get install python3-dev
* apt-get install python-dev
* If you're building Python by yourself, please rebuild your Python with `--enable-shared` (or, `--enable-framework` on Darwin)
I tried brew install python3-dev and brew install python-dev:
==> Searching for a previously deleted formula (in the last month)...
Error: No previously deleted formula found.
==> Searching taps on GitHub...
Error: No formulae found in taps.
I ran following commands but all of them caused the same error: brew reinstall python,PYTHON_CONFIGURE_OPTS="--enable-shared" pyenv install 3.9.0,PYTHON_CONFIGURE_OPTS="--enable-framework" pyenv install 3.9.0.
Uninstalling and installing pyinstall didn't work.
Does anyone has a clue?
Here's the results of the following commands:
which pyinstaller
/Users/user/.pyenv/shims/pyinstaller
which python
/Users/user/.pyenv/shims/python
I think that pyenv might have failed to install 3.9.0 the second time with the flag you needed.
The way I got it to work was to uninstall the version of python I wanted to use and then reinstall it with this command:
env PYTHON_CONFIGURE_OPTS="--enable-framework" pyenv install 3.10.2
Then to get the correct version activated, I had to run:
pyenv rehash
Otherwise, I couldn't get my system to "see" the newly re-installed version.
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 getting an error Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed? when trying to install lxml through pip.
c:\users\f\appdata\local\temp\xmlXPathInitqjzysz.c(1) : fatal error C1083: Cannot open include file: 'libxml/xpath.h': No such file or directory
*********************************************************************************
Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?
*********************************************************************************
error: command 'C:\\Users\\f\\AppData\\Local\\Programs\\Common\\Microsoft\\Visual C++ for Python\\9.0\\VC\\Bin\\cl.exe' failed with exit status 2
I don't find any libxml2 dev packages to install via pip.
Using Python 2.7 and Python 3.x on x86 in a virtualenv under Windows 10.
Install lxml from http://www.lfd.uci.edu/~gohlke/pythonlibs/#lxml for your python version. It's a precompiled WHL with required modules/dependencies.
The site lists several packages, when e.g. using Win32 Python 3.11, use lxml‑4.9.0‑cp311‑cp311‑win32.whl.
Download the file, and then install with:
pip install C:\path\to\downloaded\file\lxml‑4.9.0‑cp311‑cp311‑win32.whl
I had this issue and realised that whilst I did have libxml2 installed, I didn't have the necessary development libraries required by the python package. Installing them solved the problem:
sudo apt-get install libxml2-dev libxslt1-dev
sudo pip install lxml
Try to use:
easy_install lxml
That works for me, win10, python 2.7.
On Mac OS X El Capitan I had to run these two commands to fix this error:
xcode-select --install
pip install lxml
Which ended up installing lxml-3.5.0
When you run the xcode-select command you may have to sign a EULA (so have an X-Term handy for the UI if you're doing this on a headless machine).
In case anyone else has the same issue as this on
Centos, try:
yum install python-lxml
Ubuntu
sudo apt-get install -y python-lxml
worked for me.
set STATICBUILD=true && pip install lxml
run this command instead, must have VS C++ compiler installed first
https://blogs.msdn.microsoft.com/pythonengineering/2016/04/11/unable-to-find-vcvarsall-bat/
It works for me with Python 3.5.2 and Windows 7
I tried install a lib that depends lxml and nothing works. I see a message when build was started: "Building without Cython", so after install cython with apt-get install cython, lxml was installed.
I had this issue and realized that while I did have libxml2 installed, I didn't have the necessary development libraries required by the python package.
1) Installing them solved the problem:
The site to download the file: Download
2) After Installing the file save it in a accessible folder
pip install *path to that file*
For some reason it doesn't work in python 3.11, but 3.10 works.
On windows, to install a module with a previous version, use
py -3.10 -m pip install lxml
if you want to install it in a venv, then use
py -3.10 -m venv .venv
.venv/Scripts/pip.exe install lxml
if you've set up the venv, then you can just use
pip install lxml
You also need to run the python program with that version. If you set up a venv, then you don't need to do this.
py -3.10 file.py
It is not strange for me that none of the solutions above came up, but I saw how the igd installation removed the new version and installed the old one, for the solution I downloaded this archive:https://pypi.org/project/igd/#files
and changed the recommended version of the new version: 'lxml==4.3.0' in setup.py
It works!
I got the same error for python 32 bit. After install 64bit, the problem was fixed.
I am using venv.
In my case it was enough to add lxml==4.6.3 to requirements.txt.
One library wanted earlier version and this was causing this error, so when I forced pip to use newest version (currently 4.6.3) installation was successful.
I installed Mercurial on my Mac, and it's wonderful. For me it's easier to grasp than Git so I wanted to use it to manage git-repositories. Therefore I installed hg-git with the following instructions:
http://hg-git.github.com/
However, each time I issue a hg command it returns this error message:
Mercurial error *** failed to import extension hggit: No module named hggit
It might be important to note that I'm on a Mac not Gnu/Linux or MS-Windows.
Does any one know how to resolve this?
Note for ubuntu users who install the "mercurial-git" package to get the hggit module on 12.04 some bright spark randomly renamed the module to just "git" so you need to change your ~/.hgrc to look something like
[extensions]
hgext.bookmarks =
git =
After installing hg-git with the following command:
easy_install hg-git
Does the following work?
python -c "import hggit"
What does this say for you:
head -n1 `which hg`
The point of the latter command is to verify that the Python hg runs under has hggit installed. In my case it says '#!/usr/bin/python', which is my standard python command.
What does this say:
/opt/local/Library/Frameworks/Python.framework/Versions/2.6/Resources/Python.app/Contents/MacOS/Python -c "import hggit"
I installed Python and TortoiseHg by:
brew cask install python
brew cask install tortoisehg
After following installation
sudo easy_install hg-git
I experienced similar problems (TortoiseHg: failed to import extension hggit: No module named hggit and so on...) and finally found a solution for my TortoiseHg on mac (first uninstall last hg-git by sudo pip uninstall hg-git):
sudo pip install mercurial
sudo pip install hg-git
After installation with pip and adding bookmarks to all important branches, e. g. ...
hg bookmark -r default master
hg bookmark -r branchename bookmarkname
... I could push HG repository to Git:
hg push git+ssh://git#gitlab.URL/reponame.git --traceback
Note: use ssh! - causes fewer problems with large repositories
Note 2: --traceback tells you about problems
I got this error as well even after downloading the latest Tortoisehg and making sure the hggit plugin was installed as well as my .ini & hgrc files had the right entry to enable hggit.
Turns out my problem was that I had both mercurial and tortoisehg in my path. So when I ran any hg commands, it was using the hg.exe in mercurial folder as opposed to the hg.exe in the torsoisehg directory.
This makes sense but my mercurial installation did not have the plug ins. My fix was to remove mercurial from my path so hg commands go through the tortoisehg directory since it has hg completely bundled. Note however, the recommended option might be to upgrade mercurual to a version that has the plugins that one needs but this is what worked for me. I tried replacing the library.zip in mercurial with the one in tortoisehg and this worked but it led to other errors as one would imagine.
I had the same problem as I saw via brew install mercurial some packages are missing.
Do a test if any package missed like: python -c "import hggit"
My fix: Uninstall all packages:
brew uninstall mercurial
install with pip like:
sudo easy_install pip ( if you don't have pip )
sudo pip install mercurial and
sudo pip install hg-git
then
hg bookmark -r default master
I had the same problem, and found that installing hg-git and dulwich via easy_install worked if I used the --user option. This installed the package into ~/Library/Python/2.7/lib/python/site-packages.
To see where this option will install a package on your machine, run easy_install --help. By the documentation for the --user option, it shows the install directory that will be used.
clone hggit from http://bitbucket.org/durin42/hg-git
get hg-git path from your local computer. in my local computer /Users/coco/go/src/bitbucket.org/durin42/hg-git/hggit
add path to ~.hgrc file using your text editor
add the following lines of code
[extenstions]
hggit = /Users/coco/go/src/bitbucket.org/durin42/hg-git/hggit
try to hg clone/push/pull form github