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Python get-pip.py fails due to site-package not writtable and SSL not available while they seem OK [duplicate]

I've install Python 3.4 and Python 3.6 on my local machine successfully, but am unable to install packages with pip3.
When I execute pip3 install <package>, I get the following SSL related error:
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting <package>
Could not fetch URL https://pypi.python.org/simple/<package>/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping
Could not find a version that satisfies the requirement <package> (from versions: )
No matching distribution found for <package>
How can I fix my Python3.x install so that I can install packages with pip install <package>?

Step by step guide to install Python 3.6 and pip3 in Ubuntu
Install the necessary packages for Python and ssl: $ sudo apt-get install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev
Download and unzip "Python-3.6.8.tar.xz" from https://www.python.org/ftp/python/ into your home directory.
Open terminal in that directory and run: $ ./configure
Build and install: $ make && sudo make install
Install packages with: $ pip3 install package_name
Disclaimer: The above commands are not tested in Ubuntu 20.04 LTS.

If you are on Windows and use anaconda this worked for me:
I tried a lot of other solutions which did not work (Environment PATH Variable changes ...)
The problem can be caused by DLLs in the Windows\System32 folder (e.g. libcrypto-1_1-x64.dll or libssl-1_1-x64.dll or others) placed there by other software.
The fix was installing openSSL from https://slproweb.com/products/Win32OpenSSL.html which replaces the dlls by more recent versions.

If you are on Red Hat/CentOS:
# To allow for building python ssl libs
yum install openssl-devel
# Download the source of *any* python version
cd /usr/src
wget https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz
tar xf Python-3.6.2.tar.xz
cd Python-3.6.2
# Configure the build w/ your installed libraries
./configure
# Install into /usr/local/bin/python3.6, don't overwrite global python bin
make altinstall

I had a similar problem on OSX 10.11 due to installing memcached which installed python 3.7 on top of 3.6.
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Spent hours on unlinking openssl, reinstalling, changing paths.. and nothing helped. Changing openssl version back from to older version did the trick:
brew switch openssl 1.0.2e
I did not see this suggestion anywhere in internet. Hope it serves someone.

In Ubuntu, this can help:
cd Python-3.6.2
./configure --with-ssl
make
sudo make install

Agree with the answer by mastaBlasta. Worked for me. I encountered the same problem as the topic description.
Environment: MacOS Sierra. And I use Homebrew.
My solution:
Reinstall openssl by brew uninstall openssl; brew install openssl
According to the hints given by Homebrew, do the following:
echo 'export PATH="/usr/local/opt/openssl/bin:$PATH"' >> ~/.bash_profile
export LDFLAGS="-L/usr/local/opt/openssl/lib"
export CPPFLAGS="-I/usr/local/opt/openssl/include"

I had the same issue with python3.8.5 installation on Debian9. I have done a build, but when I have tried to download some modules, pip3.8 issued following error:
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
I have searched for the root of my problem and found out that there is a system dependent portion of the python build which is called by system independent one. In case of missing ssl you just needed to open python terminal and check whether is _ssl present:
>>> help('modules')
.
.
_sre enum pwd wave
_ssl errno py_compile weakref
_stat faulthandler pyclbr webbrowser
.
.
If not your system dependent ssl module part is missing. You can check it also by listing content of <python_installation_root>/lib/python3.8/lib-dynload:
>ls ./lib/python3.8/lib-dynload | grep ssl
_ssl.cpython-38-x86_64-linux-gnu.so
The problem was caused as written by PengShaw by missing libssl-dev during the build. Therefore you have to follow the recommended python installation flow. First install prerequisites and then build and install the python. Installation without devel versions of libs resulted in my case in the missing system dependent part. In this case _ssl.
Note that the devel lib name differs for Debian and CentOS, therefore check whether the installation hints posted on net are suitable for your specific Linux system type:
For Debian:
sudo apt install -y libbz2-dev libffi-dev libssl-dev
./configure --enable-optimizations
make
make altinstall
For CentOS:
sudo yum -y install bzip2-devel libffi-devel openssl-devel
./configure --enable-optimizations
make
make altinstall
It is for sure a good idea to list configuration options prior the configuration and evtl. use some additional options:
./configure --help
Last but not least in case you use --prefix for a non-default installation location, remember to add your <python_installation_root>/lib to your LD_LIBRARY_PATH .

If you are on Windows and use Anaconda you can try running "pip install ..." command in Anaconda Prompt instead of cmd.exe, as user willliu1995 suggests here. This was the fastest solution for me, that does not require installation of additional components.

The problem probably caused by library missing.
Before you install python 3.6, make sure you install all the libraries required for python.
$ sudo apt-get install build-essential checkinstall
$ sudo apt-get install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev
More information in How to Install Python 3.6.0 on Ubuntu & LinuxMint

If you are on OSX and have compiled python from source:
Install openssl using brew brew install openssl
Make sure to follow the instructions brew gives you about setting your CPPFLAGS and LDFLAGS. In my case I am using the openssl#1.1 brew formula and I need these 3 settings for the python build process to correctly link to my SSL library:
export LDFLAGS="-L/usr/local/opt/openssl#1.1/lib"
export CPPFLAGS="-I/usr/local/opt/openssl#1.1/include"
export PKG_CONFIG_PATH="/usr/local/opt/openssl#1.1/lib/pkgconfig"
Assuming the library is installed at that location.

Downgrading openssl worked for me,
brew switch openssl 1.0.2s

I encountered the same problem on windows 10. My very specific issue is due to my installation of Anaconda. I installed Anaconda and under the path Path/to/Anaconda3/, there comes the python.exe. Thus, I didn't install python at all because Anaconda includes python. When using pip to install packages, I found the same error report, pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available..
The solution was the following:
1) you can download python again on the official website;
2) Navigate to the directory where "Python 3.7 (64-bit).lnk"is located
3) import ssl and exit()
4) type in cmd, "Python 3.7 (64-bit).lnk" -m pip install tensorflow for instance.
Here, you're all set.

I tried A LOT of ways to solve this problem and none solved. I'm currently on Windows 10.
The only thing that worked was:
Uninstall Anaconda
Uninstall Python (i was using version 3.7.3)
Install Python again (remember to check the option to automatically add to PATH)
Then I've downloaded all the libs I needed using PIP... and worked!
Don't know why, or if the problem was somehow related to Anaconda.

for osx brew users
my issue appeared related to my python installation and was quickly resolved by re-installing python3 and pip. i think it started misbehaving after an OS update but who knows (at this time I am on Mac OS 10.14.6)
brew reinstall python3 --force
# setup pip
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python3 get-pip.py
# installa pkg successfully
pip install pandas

You can do either of these two:
While installing Anaconda, select the option to add Anaconda to the path.
or
Find these (complete) paths from your installation folder of Anaconda and add them to the environment variable :
\Anaconda
\Anaconda\Library\mingw-w64\bin
\Anaconda\Library\usr\bin
\Anaconda\Library\bin
\Anaconda\Scripts
\anaconda\Library
\anaconda\condabin
Add the above paths to the "Path" system variable and it should show the error no more :)

The ssl module is a TLS/SSL wrapper for accessing Operation Sytem (OS) socket (Lib/ssl.py). So when ssl module is not available, chances are that you either don't have OS OpenSSL libraries installed, or those libraries were not found when you install Python. Let assume it is a later case (aka: you already have OpenSSL installed, but they are not correctly linked when installing Python).
I will also assume you are installing from source. If you are installing from binary (ie: Window .exe file), or package (Mac .dmg, or Ubuntu apt), there is not much you can do with the installing process.
During the step of configuring your python installation, you need to specify where the OS OpenSSL will be used for linking:
# python 3.8 beta
./configure --with-openssl="your_OpenSSL root"
So where will you find your installed OpenSSL directory?
# ubuntu
locate ssl.h | grep '/openssl/ssl.h'
/home/user/.linuxbrew/Cellar/openssl/1.0.2r/include/openssl/ssl.h
/home/user/envs/py37/include/openssl/ssl.h
/home/user/miniconda3/envs/py38b3/include/openssl/ssl.h
/home/user/miniconda3/include/openssl/ssl.h
/home/user/miniconda3/pkgs/openssl-1.0.2s-h7b6447c_0/include/openssl/ssl.h
/home/user/miniconda3/pkgs/openssl-1.1.1b-h7b6447c_1/include/openssl/ssl.h
/home/user/miniconda3/pkgs/openssl-1.1.1c-h7b6447c_1/include/openssl/ssl.h
/usr/include/openssl/ssl.h
Your system may be different than mine, but as you see here I have many different installed openssl libraries. As the time of this writing, python 3.8 expects openssl 1.0.2 or 1.1:
Python requires an OpenSSL 1.0.2 or 1.1 compatible libssl with X509_VERIFY_PARAM_set1_host().
So you would need to verify which of those installed libraries that you can use for linking, for example
/usr/bin/openssl version
OpenSSL 1.0.2g 1 Mar 2016
./configure --with-openssl="/usr"
make && make install
You may need to try a few, or install a new, to find the library that would work for your Python and your OS.

I was having the same issue and was able to resolve with the following steps:
sudo yum install -y libffi-devel
sudo yum install openssl-devel
cd /usr/src
sudo wget https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tar.xz
sudo tar xf Python-3.7.1.tar.xz
cd Python-3.7.1
sudo ./configure --enable-optimizations
# Install into /usr/local/bin/python3.7, don't overwrite global python bin
sudo make altinstall
depending on perms, you may not need sudo.
Results:
Collecting setuptools
Collecting pip
Installing collected packages: setuptools, pip
Successfully installed pip-10.0.1 setuptools-39.0.1
should now be able to run
python3.7 -V
and
pip3.7 -V
When installing packages:
pip3.7 install pandas
or depending on perms, you can also add the --user flag like so:
pip3.7 install pandas --user

In my case with using Mac, I deleted
/Applications/Python 3.7.
because I already had Python3.7 by brew install python3 .
But it was a trigger of the message
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
What I did in my situation
I downloaded macOS 64-bit installer again, and installed.
Double click /Applications/Python3.6/Install Certificates.command and /Applications/Python3.6/Update Shell Profile.command.
Reboot mac
And I am not sure but possibly contributed to succeed is pip.conf. See pip install fails.

I finally solve this issue. These are the detail of my env:
Version of Python to install: 3.6.8
OS: Ubuntu 16.04.6 LTS
Root access: No
Some people suggest to install libssl-dev, but it did not work for me. I follow this link and I fixed it!
In short, I download, extract, build, and install OpenSSL (openssl-1.1.1b.tar.gz). Then, I modify .bashrc file follow this link.
Next, I download and extract Python-3.6.8.tgz. I edit Modules/Setup.dist to modify SSL path (lines around #211). I did ./configure --prefix=$HOME/opt/python-3.6.8, make and make install. Last, I modify my .bashrc. Notice that I do not include --enable-optimizations in ./configure.

I was able to fix this by updating the python version in this file.
pyenv: version `3.6.5' is not installed (set by /Users/taruntarun/.python-version)
Though i had the latest version installed, my command was still using old version 3.6.5
Moving to version 3.7.3

Termux
This worked because i didnt have an existing openssl version installed.
pkg install openssl-tool

If you are on OSX and in case the other solutions didn't work for you (just like me).
You can try uninstalling python3 and upgrade pip3
brew uninstall --ignore-dependencies python3
pip3 install --upgrade pip
This worked for me ;)

(NOT on Windows!)
This made me tear my hair out for a week, so I hope this will help someone
I tried everything short of re-installing Anaconda and/or Jupyter.
Setup
AWS Linux
Manually installed Anaconda 3-5.3.0
Python3 (3.7) was running inside anaconda (ie, ./anaconda3/bin/python)
there was also /usr/bin/python and /usr/bin/python3 (but these were not being used as most of the work was done in Jupyter's terminal)
Fix
In Jupyter's terminal:
cp /usr/lib64/libssl.so.10 ./anaconda3/lib/libssl.so.1.0.0
cp /usr/lib64/libcrypto.so.10 ./anaconda3/lib/libcrypto.so.1.0.0
What triggered this?
So, this was all working until I tried to do a conda install conda-forge
I'm not sure what happened, but conda must have updated openssl on the box (I'm guessing) so after this, everything broke.
Basically, unknown to me, conda had updated openssl, but somehow deleted the old libraries and replaced it with libssl.so.1.1 and libcrypto.so.1.1.
Python3, I guess, was compiled to look for libssl.so.1.0.0
In the end, the key to diagnosis was this:
python -c "import ssl; print (ssl.OPENSSL_VERSION)"
gave the clue library "libssl.so.1.0.0" not found
The huge assumption I made is that the yum version of ssl is the same as the conda version, so just renaming the shared object might work, and it did.
My other solution was to re-compile python, re-install anaconda, etc, but in the end I'm glad I didn't need to.
Hope this helps you guys out.

In the case of using pyenv to manage python installations on Mac OS Catalina, I had to install openssl with brew first and then after that run pyenv install 3.7.8 which seemed to build the python installation using the openssl from homebrew (it even said as such in the installation output). Then pyenv global 3.7.8 and I was away.

On macos, configure python 3.8.1 with the command below will solve the problem, i think it would also work on Linux.
./configure --enable-optimizations --with-openssl=/usr/local/opt/openssl#1.1/
change the dir parameter based on your system.

I've made some PATH changes to mimic part of the Anaconda Powershell Prompt $env:PATH
C:\Users\merheb\Miniconda3;C:\Users\merheb\Miniconda3\Library\mingw-w64\bin;C:\Users\merheb\Miniconda3\Library\usr\bin;C:\Users\merheb\Miniconda3\Library\bin;C:\Users\merheb\Miniconda3\Scripts;C:\Users\merheb\Miniconda3\bin;C:\Users\merheb\Miniconda3\condabin;
And It worked for me.

Building from source was what worked for me on Ubuntu 22.10:
Install OpenSSL manually, tested here with OpenSSL 1.1.1s, extracted then ran:
./config --prefix='/opt/openssl' --openssldir='/opt/ssl'
make
make install
Then with your older Python 3 version (here Python-3.8.16) run:
export LD_RUN_PATH='/opt/openssl/lib'
export CC='gcc-12' # sudo apt install gcc-12
./configure --enable-optimizations \
--with-openssl='/opt/openssl' \
--prefix='/opt/python/3.8' -C
make
make install
Test with:
/opt/python/3.8/bin/python3 -c 'import ssl; print(ssl.OPENSSL_VERSION)'
OpenSSL 1.1.1s 1 Nov 2022

The python documentation is actually very clear, and following the instructions did the job whereas other answers I found here were not fixing this issue.
first, install python 3.x.x from source using, for example with version 3.6.2 https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz
make sure you have openssl installed by running brew install openssl
unzip it and move to the python directory: tar xvzf Python-3.6.2.tar.xz && cd Python-3.6.2
then if the python version is < 3.7, run
CPPFLAGS="-I$(brew --prefix openssl)/include" \
LDFLAGS="-L$(brew --prefix openssl)/lib" \
./configure --with-pydebug
5. finallly, run make -s -j2 (-s is the silent flag, -j2 tells your machine to use 2 jobs)

I had the same issue trying to install python3.7 on an ubuntu14.04 machine.
The issue was that I had some custom folders in my PKG_CONFIG_PATH and in my LD_LIBRARY_PATH, which prevented the python build process to find the system openssl libraries.
so try to clear them and see what happens:
export PKG_CONFIG_PATH=""
export LD_LIBRARY_PATH=""

Ok the latest answer to this, as of now don't use Python 3.8, use only 3.7 or less , because of most of the libraries fail to install with the above error

Problems with Python installing anything [duplicate]

I've install Python 3.4 and Python 3.6 on my local machine successfully, but am unable to install packages with pip3.
When I execute pip3 install <package>, I get the following SSL related error:
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting <package>
Could not fetch URL https://pypi.python.org/simple/<package>/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping
Could not find a version that satisfies the requirement <package> (from versions: )
No matching distribution found for <package>
How can I fix my Python3.x install so that I can install packages with pip install <package>?

Step by step guide to install Python 3.6 and pip3 in Ubuntu
Install the necessary packages for Python and ssl: $ sudo apt-get install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev
Download and unzip "Python-3.6.8.tar.xz" from https://www.python.org/ftp/python/ into your home directory.
Open terminal in that directory and run: $ ./configure
Build and install: $ make && sudo make install
Install packages with: $ pip3 install package_name
Disclaimer: The above commands are not tested in Ubuntu 20.04 LTS.

If you are on Windows and use anaconda this worked for me:
I tried a lot of other solutions which did not work (Environment PATH Variable changes ...)
The problem can be caused by DLLs in the Windows\System32 folder (e.g. libcrypto-1_1-x64.dll or libssl-1_1-x64.dll or others) placed there by other software.
The fix was installing openSSL from https://slproweb.com/products/Win32OpenSSL.html which replaces the dlls by more recent versions.

If you are on Red Hat/CentOS:
# To allow for building python ssl libs
yum install openssl-devel
# Download the source of *any* python version
cd /usr/src
wget https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz
tar xf Python-3.6.2.tar.xz
cd Python-3.6.2
# Configure the build w/ your installed libraries
./configure
# Install into /usr/local/bin/python3.6, don't overwrite global python bin
make altinstall

I had a similar problem on OSX 10.11 due to installing memcached which installed python 3.7 on top of 3.6.
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Spent hours on unlinking openssl, reinstalling, changing paths.. and nothing helped. Changing openssl version back from to older version did the trick:
brew switch openssl 1.0.2e
I did not see this suggestion anywhere in internet. Hope it serves someone.

In Ubuntu, this can help:
cd Python-3.6.2
./configure --with-ssl
make
sudo make install

Agree with the answer by mastaBlasta. Worked for me. I encountered the same problem as the topic description.
Environment: MacOS Sierra. And I use Homebrew.
My solution:
Reinstall openssl by brew uninstall openssl; brew install openssl
According to the hints given by Homebrew, do the following:
echo 'export PATH="/usr/local/opt/openssl/bin:$PATH"' >> ~/.bash_profile
export LDFLAGS="-L/usr/local/opt/openssl/lib"
export CPPFLAGS="-I/usr/local/opt/openssl/include"

I had the same issue with python3.8.5 installation on Debian9. I have done a build, but when I have tried to download some modules, pip3.8 issued following error:
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
I have searched for the root of my problem and found out that there is a system dependent portion of the python build which is called by system independent one. In case of missing ssl you just needed to open python terminal and check whether is _ssl present:
>>> help('modules')
.
.
_sre enum pwd wave
_ssl errno py_compile weakref
_stat faulthandler pyclbr webbrowser
.
.
If not your system dependent ssl module part is missing. You can check it also by listing content of <python_installation_root>/lib/python3.8/lib-dynload:
>ls ./lib/python3.8/lib-dynload | grep ssl
_ssl.cpython-38-x86_64-linux-gnu.so
The problem was caused as written by PengShaw by missing libssl-dev during the build. Therefore you have to follow the recommended python installation flow. First install prerequisites and then build and install the python. Installation without devel versions of libs resulted in my case in the missing system dependent part. In this case _ssl.
Note that the devel lib name differs for Debian and CentOS, therefore check whether the installation hints posted on net are suitable for your specific Linux system type:
For Debian:
sudo apt install -y libbz2-dev libffi-dev libssl-dev
./configure --enable-optimizations
make
make altinstall
For CentOS:
sudo yum -y install bzip2-devel libffi-devel openssl-devel
./configure --enable-optimizations
make
make altinstall
It is for sure a good idea to list configuration options prior the configuration and evtl. use some additional options:
./configure --help
Last but not least in case you use --prefix for a non-default installation location, remember to add your <python_installation_root>/lib to your LD_LIBRARY_PATH .

If you are on Windows and use Anaconda you can try running "pip install ..." command in Anaconda Prompt instead of cmd.exe, as user willliu1995 suggests here. This was the fastest solution for me, that does not require installation of additional components.

The problem probably caused by library missing.
Before you install python 3.6, make sure you install all the libraries required for python.
$ sudo apt-get install build-essential checkinstall
$ sudo apt-get install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev
More information in How to Install Python 3.6.0 on Ubuntu & LinuxMint

If you are on OSX and have compiled python from source:
Install openssl using brew brew install openssl
Make sure to follow the instructions brew gives you about setting your CPPFLAGS and LDFLAGS. In my case I am using the openssl#1.1 brew formula and I need these 3 settings for the python build process to correctly link to my SSL library:
export LDFLAGS="-L/usr/local/opt/openssl#1.1/lib"
export CPPFLAGS="-I/usr/local/opt/openssl#1.1/include"
export PKG_CONFIG_PATH="/usr/local/opt/openssl#1.1/lib/pkgconfig"
Assuming the library is installed at that location.

Downgrading openssl worked for me,
brew switch openssl 1.0.2s

I encountered the same problem on windows 10. My very specific issue is due to my installation of Anaconda. I installed Anaconda and under the path Path/to/Anaconda3/, there comes the python.exe. Thus, I didn't install python at all because Anaconda includes python. When using pip to install packages, I found the same error report, pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available..
The solution was the following:
1) you can download python again on the official website;
2) Navigate to the directory where "Python 3.7 (64-bit).lnk"is located
3) import ssl and exit()
4) type in cmd, "Python 3.7 (64-bit).lnk" -m pip install tensorflow for instance.
Here, you're all set.

I tried A LOT of ways to solve this problem and none solved. I'm currently on Windows 10.
The only thing that worked was:
Uninstall Anaconda
Uninstall Python (i was using version 3.7.3)
Install Python again (remember to check the option to automatically add to PATH)
Then I've downloaded all the libs I needed using PIP... and worked!
Don't know why, or if the problem was somehow related to Anaconda.

for osx brew users
my issue appeared related to my python installation and was quickly resolved by re-installing python3 and pip. i think it started misbehaving after an OS update but who knows (at this time I am on Mac OS 10.14.6)
brew reinstall python3 --force
# setup pip
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python3 get-pip.py
# installa pkg successfully
pip install pandas

You can do either of these two:
While installing Anaconda, select the option to add Anaconda to the path.
or
Find these (complete) paths from your installation folder of Anaconda and add them to the environment variable :
\Anaconda
\Anaconda\Library\mingw-w64\bin
\Anaconda\Library\usr\bin
\Anaconda\Library\bin
\Anaconda\Scripts
\anaconda\Library
\anaconda\condabin
Add the above paths to the "Path" system variable and it should show the error no more :)

The ssl module is a TLS/SSL wrapper for accessing Operation Sytem (OS) socket (Lib/ssl.py). So when ssl module is not available, chances are that you either don't have OS OpenSSL libraries installed, or those libraries were not found when you install Python. Let assume it is a later case (aka: you already have OpenSSL installed, but they are not correctly linked when installing Python).
I will also assume you are installing from source. If you are installing from binary (ie: Window .exe file), or package (Mac .dmg, or Ubuntu apt), there is not much you can do with the installing process.
During the step of configuring your python installation, you need to specify where the OS OpenSSL will be used for linking:
# python 3.8 beta
./configure --with-openssl="your_OpenSSL root"
So where will you find your installed OpenSSL directory?
# ubuntu
locate ssl.h | grep '/openssl/ssl.h'
/home/user/.linuxbrew/Cellar/openssl/1.0.2r/include/openssl/ssl.h
/home/user/envs/py37/include/openssl/ssl.h
/home/user/miniconda3/envs/py38b3/include/openssl/ssl.h
/home/user/miniconda3/include/openssl/ssl.h
/home/user/miniconda3/pkgs/openssl-1.0.2s-h7b6447c_0/include/openssl/ssl.h
/home/user/miniconda3/pkgs/openssl-1.1.1b-h7b6447c_1/include/openssl/ssl.h
/home/user/miniconda3/pkgs/openssl-1.1.1c-h7b6447c_1/include/openssl/ssl.h
/usr/include/openssl/ssl.h
Your system may be different than mine, but as you see here I have many different installed openssl libraries. As the time of this writing, python 3.8 expects openssl 1.0.2 or 1.1:
Python requires an OpenSSL 1.0.2 or 1.1 compatible libssl with X509_VERIFY_PARAM_set1_host().
So you would need to verify which of those installed libraries that you can use for linking, for example
/usr/bin/openssl version
OpenSSL 1.0.2g 1 Mar 2016
./configure --with-openssl="/usr"
make && make install
You may need to try a few, or install a new, to find the library that would work for your Python and your OS.

I was having the same issue and was able to resolve with the following steps:
sudo yum install -y libffi-devel
sudo yum install openssl-devel
cd /usr/src
sudo wget https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tar.xz
sudo tar xf Python-3.7.1.tar.xz
cd Python-3.7.1
sudo ./configure --enable-optimizations
# Install into /usr/local/bin/python3.7, don't overwrite global python bin
sudo make altinstall
depending on perms, you may not need sudo.
Results:
Collecting setuptools
Collecting pip
Installing collected packages: setuptools, pip
Successfully installed pip-10.0.1 setuptools-39.0.1
should now be able to run
python3.7 -V
and
pip3.7 -V
When installing packages:
pip3.7 install pandas
or depending on perms, you can also add the --user flag like so:
pip3.7 install pandas --user

In my case with using Mac, I deleted
/Applications/Python 3.7.
because I already had Python3.7 by brew install python3 .
But it was a trigger of the message
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
What I did in my situation
I downloaded macOS 64-bit installer again, and installed.
Double click /Applications/Python3.6/Install Certificates.command and /Applications/Python3.6/Update Shell Profile.command.
Reboot mac
And I am not sure but possibly contributed to succeed is pip.conf. See pip install fails.

I finally solve this issue. These are the detail of my env:
Version of Python to install: 3.6.8
OS: Ubuntu 16.04.6 LTS
Root access: No
Some people suggest to install libssl-dev, but it did not work for me. I follow this link and I fixed it!
In short, I download, extract, build, and install OpenSSL (openssl-1.1.1b.tar.gz). Then, I modify .bashrc file follow this link.
Next, I download and extract Python-3.6.8.tgz. I edit Modules/Setup.dist to modify SSL path (lines around #211). I did ./configure --prefix=$HOME/opt/python-3.6.8, make and make install. Last, I modify my .bashrc. Notice that I do not include --enable-optimizations in ./configure.

I was able to fix this by updating the python version in this file.
pyenv: version `3.6.5' is not installed (set by /Users/taruntarun/.python-version)
Though i had the latest version installed, my command was still using old version 3.6.5
Moving to version 3.7.3

Termux
This worked because i didnt have an existing openssl version installed.
pkg install openssl-tool

If you are on OSX and in case the other solutions didn't work for you (just like me).
You can try uninstalling python3 and upgrade pip3
brew uninstall --ignore-dependencies python3
pip3 install --upgrade pip
This worked for me ;)

(NOT on Windows!)
This made me tear my hair out for a week, so I hope this will help someone
I tried everything short of re-installing Anaconda and/or Jupyter.
Setup
AWS Linux
Manually installed Anaconda 3-5.3.0
Python3 (3.7) was running inside anaconda (ie, ./anaconda3/bin/python)
there was also /usr/bin/python and /usr/bin/python3 (but these were not being used as most of the work was done in Jupyter's terminal)
Fix
In Jupyter's terminal:
cp /usr/lib64/libssl.so.10 ./anaconda3/lib/libssl.so.1.0.0
cp /usr/lib64/libcrypto.so.10 ./anaconda3/lib/libcrypto.so.1.0.0
What triggered this?
So, this was all working until I tried to do a conda install conda-forge
I'm not sure what happened, but conda must have updated openssl on the box (I'm guessing) so after this, everything broke.
Basically, unknown to me, conda had updated openssl, but somehow deleted the old libraries and replaced it with libssl.so.1.1 and libcrypto.so.1.1.
Python3, I guess, was compiled to look for libssl.so.1.0.0
In the end, the key to diagnosis was this:
python -c "import ssl; print (ssl.OPENSSL_VERSION)"
gave the clue library "libssl.so.1.0.0" not found
The huge assumption I made is that the yum version of ssl is the same as the conda version, so just renaming the shared object might work, and it did.
My other solution was to re-compile python, re-install anaconda, etc, but in the end I'm glad I didn't need to.
Hope this helps you guys out.

In the case of using pyenv to manage python installations on Mac OS Catalina, I had to install openssl with brew first and then after that run pyenv install 3.7.8 which seemed to build the python installation using the openssl from homebrew (it even said as such in the installation output). Then pyenv global 3.7.8 and I was away.

On macos, configure python 3.8.1 with the command below will solve the problem, i think it would also work on Linux.
./configure --enable-optimizations --with-openssl=/usr/local/opt/openssl#1.1/
change the dir parameter based on your system.

I've made some PATH changes to mimic part of the Anaconda Powershell Prompt $env:PATH
C:\Users\merheb\Miniconda3;C:\Users\merheb\Miniconda3\Library\mingw-w64\bin;C:\Users\merheb\Miniconda3\Library\usr\bin;C:\Users\merheb\Miniconda3\Library\bin;C:\Users\merheb\Miniconda3\Scripts;C:\Users\merheb\Miniconda3\bin;C:\Users\merheb\Miniconda3\condabin;
And It worked for me.

Building from source was what worked for me on Ubuntu 22.10:
Install OpenSSL manually, tested here with OpenSSL 1.1.1s, extracted then ran:
./config --prefix='/opt/openssl' --openssldir='/opt/ssl'
make
make install
Then with your older Python 3 version (here Python-3.8.16) run:
export LD_RUN_PATH='/opt/openssl/lib'
export CC='gcc-12' # sudo apt install gcc-12
./configure --enable-optimizations \
--with-openssl='/opt/openssl' \
--prefix='/opt/python/3.8' -C
make
make install
Test with:
/opt/python/3.8/bin/python3 -c 'import ssl; print(ssl.OPENSSL_VERSION)'
OpenSSL 1.1.1s 1 Nov 2022

The python documentation is actually very clear, and following the instructions did the job whereas other answers I found here were not fixing this issue.
first, install python 3.x.x from source using, for example with version 3.6.2 https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz
make sure you have openssl installed by running brew install openssl
unzip it and move to the python directory: tar xvzf Python-3.6.2.tar.xz && cd Python-3.6.2
then if the python version is < 3.7, run
CPPFLAGS="-I$(brew --prefix openssl)/include" \
LDFLAGS="-L$(brew --prefix openssl)/lib" \
./configure --with-pydebug
5. finallly, run make -s -j2 (-s is the silent flag, -j2 tells your machine to use 2 jobs)

I had the same issue trying to install python3.7 on an ubuntu14.04 machine.
The issue was that I had some custom folders in my PKG_CONFIG_PATH and in my LD_LIBRARY_PATH, which prevented the python build process to find the system openssl libraries.
so try to clear them and see what happens:
export PKG_CONFIG_PATH=""
export LD_LIBRARY_PATH=""

Ok the latest answer to this, as of now don't use Python 3.8, use only 3.7 or less , because of most of the libraries fail to install with the above error

No module named '_sqlite3' after Python 3.5.2 install on GoDaddy server [duplicate]

I am trying to run a Django app on my VPS running Debian 5. When I run a demo app, it comes back with this error:
File "/usr/local/lib/python2.5/site-packages/django/utils/importlib.py", line 35, in import_module
__import__(name)
File "/usr/local/lib/python2.5/site-packages/django/db/backends/sqlite3/base.py", line 30, in <module>
raise ImproperlyConfigured, "Error loading %s: %s" % (module, exc)
ImproperlyConfigured: Error loading either pysqlite2 or sqlite3 modules (tried in that order): No module named _sqlite3
Looking at the Python install, it gives the same error:
Python 2.5.2 (r252:60911, May 12 2009, 07:46:31)
[GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sqlite3
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.5/sqlite3/__init__.py", line 24, in <module>
from dbapi2 import *
File "/usr/local/lib/python2.5/sqlite3/dbapi2.py", line 27, in <module>
from _sqlite3 import *
ImportError: No module named _sqlite3
>>>
Reading on the web, I learn that Python 2.5 should come with all the necessary SQLite wrappers included. Do I need to reinstall Python, or is there another way to get this module up and running?

It seems your makefile didn't include the appropriate .so file. You can correct this problem with the steps below:
Install sqlite-devel (or libsqlite3-dev on some Debian-based systems)
Re-configure and re-compiled Python with ./configure --enable-loadable-sqlite-extensions && make && sudo make install
Note
The sudo make install part will set that python version to be the system-wide standard, which can have unforseen consequences. If you run this command on your workstation, you'll probably want to have it installed alongside the existing python, which can be done with sudo make altinstall.

I had the same problem (building python2.5 from source on Ubuntu Lucid), and import sqlite3 threw this same exception. I've installed libsqlite3-dev from the package manager, recompiled python2.5, and then the import worked.

I had the same problem with Python 3.5 on Ubuntu while using pyenv.
If you're installing the python using pyenv, it's listed as one of the common build problems. To solve it, remove the installed python version, install the requirements (for this particular case libsqlite3-dev), then reinstall the python version with
pyenv install <python-version>
Then recreate virtualenv if needed.

my python is build from source, the cause is missing options when exec configure
python version：3.7.4
./configure --enable-loadable-sqlite-extensions --enable-optimizations
make
make install
fixed

This is what I did to get it to work.
I am using pythonbrew(which is using pip) with python 2.7.5 installed.
I first did what Zubair(above) said and ran this command:
sudo apt-get install libsqlite3-dev
Then I ran this command:
pip install pysqlite
This fixed the database problem and I got confirmation of this when I ran:
python manager.py syncdb

Install the sqlite-devel package:
yum install sqlite-devel -y
Recompile python from the source:
./configure
make
make altinstall

I found lots of people meet this problem because the Multi-version Python,
on my own vps (cent os 7 x64), I solved it in this way:
Find the file "_sqlite3.so"
find / -name _sqlite3.so
out: /usr/lib64/python2.7/lib-dynload/_sqlite3.so
Find the dir of python Standard library you want to use,
for me /usr/local/lib/python3.6/lib-dynload
Copy the file:
cp /usr/lib64/python2.7/lib-dynload/_sqlite3.so /usr/local/lib/python3.6/lib-dynload
Finally, everything will be ok.

For Python 3.7.8 with Redhat 7 or Centos 7.
Install sqlite-devel
$ yum install sqlite-devel
Compile and install Python3 with sqllite extensions
$ ./configure --enable-optimizations --enable-loadable-sqlite-extensions
$ make install

My _sqlite3.so is in /usr/lib/python2.5/lib-dynload/_sqlite3.so. Judging from your paths, you should have the file /usr/local/lib/python2.5/lib-dynload/_sqlite3.so.
Try the following:
find /usr/local -name _sqlite3.so
If the file isn't found, something may be wrong with your Python installation. If it is, make sure the path it's installed to is in the Python path. In the Python shell,
import sys
print sys.path
In my case, /usr/lib/python2.5/lib-dynload is in the list, so it's able to find /usr/lib/python2.5/lib-dynload/_sqlite3.so.

I recently tried installing python 2.6.7 on my Ubuntu 11.04 desktop for some dev work. Came across similar problems to this thread. I mamaged to fix it by:
Adjusting the setup.py file to include the correct sqlite dev path. Code snippet from setup.py:
def sqlite_incdir:
sqlite_dirs_to_check = [
os.path.join(sqlite_incdir, '..', 'lib64'),
os.path.join(sqlite_incdir, '..', 'lib'),
os.path.join(sqlite_incdir, '..', '..', 'lib64'),
os.path.join(sqlite_incdir, '..', '..', 'lib'),
'/usr/lib/x86_64-linux-gnu/'
]
With the bit that I added being '/usr/lib/x86_64-linux-gnu/'.
After running make I did not get any warnings saying the sqlite support was not built (i.e., it built correctly :P ), but after running make install, sqlite3 still did not import with the same "ImportError: No module named _sqlite3" whe running "import sqlite3".
So, the library was compiled, but not moved to the correct installation path, so I copied the .so file (cp /usr/src/python/Python-2.6.7/build/lib.linux-x86_64-2.6/_sqlite3.so /usr/local/python-2.6.7/lib/python2.6/sqlite3/ — these are my build paths, you will probably need to adjust them to your setup).
Voila! SQLite3 support now works.

This worked for me in Redhat Centos 6.5:
yum install sqlite-devel
pip install pysqlite

sqlite3 ships with Python. I also had the same problem, I just uninstalled python3.6 and installed it again.
Uninstall existing python:
sudo apt-get remove --purge python3.6
Install python3.6:
sudo apt install build-essential checkinstall
sudo apt install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev
wget https://www.python.org/ftp/python/3.6.0/Python-3.6.0.tar.xz
tar xvf Python-3.6.0.tar.xz
cd Python-3.6.0/
./configure
sudo make altinstall

Is the python-pysqlite2 package installed?
sudo apt-get install python-pysqlite2

Checking your settings.py file.
Did you not just write "sqlite" instead of "sqlite3" for the database engine?

Putting answer for anyone who lands on this page searching for a solution for Windows OS:
You have to install pysqlite3 or db-sqlite3 if not already installed. you can use following to install.
pip install pysqlite3
pip install db-sqlite3
For me the issue was with DLL file of sqlite3.
Solution:
I took DLL file from sqlite site. This might vary based on your
version of python installation.
I pasted it in the DLL directory of
the env. for me it was "C:\Anaconda\Lib\DLLs", but check for yours.

I have the problem in FreeBSD 8.1:
- No module named _sqlite3 -
It is solved by stand the port ----------
/usr/ports/databases/py-sqlite3
after this one can see:
OK ----------
'>>>' import sqlite3 -----
'>>>' sqlite3.apilevel -----
'2.0'

you must be in centos or redhat and compile python yourself，
it is python‘s bug
do this in your python source code dir and do this below
curl -sk https://gist.github.com/msabramo/2727063/raw/59ea097a1f4c6f114c32f7743308a061698b17fd/gistfile1.diff | patch -p1

I was disappointed this issue still exist till today. As I have recently been trying to install vCD CLI on CentOS 8.1 and I was welcomed with the same error when tried to run it. The way I had to resolve it in my case is as follow:
Install SQLite3 from scratch with the proper prefix
Make clean my Python Installation
Run Make install to reinstall Python
As I have been doing this to create a different blogpost about how to install vCD CLI and VMware Container Service Extension. I have end up capturing the steps I used to fix the issue and put it in a separate blog post at:
http://www.virtualizationteam.com/cloud/running-vcd-cli-fail-with-the-following-error-modulenotfounderror-no-module-named-_sqlite3.html
I hope this helpful, as while the tips above had helped me get to a solution, I had to combine few of them and modify them a bit.

i got the same problem, nothing worked for me from the above ans
but now i fixed it by
just remove python.pip and sqlite3 and reinstall
sudo apt-get remove python.pip
sudo apt-get remove sqlite3
now install it again
sudo apt-get install python.pip
sudo apt-get install sqlite3
in my case while installing sqlite3 again it showed some error
then i typed
sqlite3
on terminal to check if it was removed or not and it started unpacking it
once the sqlite3 is installed
fireup terminal and write
sqlite3
database.db (to create a database)
i'm sure this will definately help you

Try installing sqlite like this if you are using FreeBSD.
pkg install py27-sqlite3-2.7.10_6

I had the same problem after installing Python 3.8.11 using asdf
To fix the issue:
I had to install libsqlite3-dev
sudo apt-get install libsqlite3-dev
Then uninstall Python via asdf
asdf uninstall python 3.8.11
And install Python again via asdf
asdf install python 3.8.11

The following worked for Python 3.9 with a virtual environment:
Install the sqlite3 library.
sudo apt-get install libsqlite3-dev
Activate the Python virtual environment.
source env/bin/activate
Copy the sqlite3 file into the Python virtual environment and rename it to support Python 3.9.
cp /usr/lib/python3.8/lib-dynload/_sqlite3.cpython-38-x86_64-linux-gnu.so ./env/lib/python3.9/site-packages
mv ./env/lib/python3.9/site-packages/_sqlite3.cpython-38-x86_64-linux-gnu.so ./env/lib/python3.9/site-packages/_sqlite3.cpython-39-x86_64-linux-gnu.so
Note, we're renaming 38 to 39 in the file name to support Python 3.9.

Download sqlite3:
wget http://www.sqlite.org/2016/sqlite-autoconf-3150000.tar.gz
Follow these steps to install:
$tar xvfz sqlite-autoconf-3071502.tar.gz
$cd sqlite-autoconf-3071502
$./configure --prefix=/usr/local
$make install

I faced this issue with multiple python dependent package while setup in python virtual enironment in Ubuntu.It is because of sqlite binding for our python.
Error I got:
from pysqlite2 import dbapi2 as sqlite3
ModuleNotFoundError: No module named 'pysqlite2'
I resolved it by --enable-loadable-sqlite-extensions=yes
1.) First find your python or python version you used for creating virtual env. I have used python3.8
e.g
$ whereis python
python: /usr/bin/python3.6m /usr/bin/python /usr/bin/python3.8 /usr/bin/python2.7-config /usr/bin/python3.8-config python
$ cd /usr/bin
$ls
python3.8
python3.8-config
Note: there will be many package check for pytho. you will find configure file for each python version, now use specific python version
ox:/usr/bin$ ./python3.8-config --enable-loadable-sqlite-extensions=yes
OR
ox:/usr/bin$ ./python3.8-config --enable-optimizations --enable-loadable-sqlite-extensions
Now, create your virtual env using that python version
e.g
Go the folder where you want to create the virtual env
$ python3.8 -m venv mlwen_jup_env
$ source mlwen_jup_env/bin/activate
Its done, now you can install packages

I ran into this same problem on a NetBSD server. A missing .so file needed to be installed using pkgin. To identify what package to install, I ran
pkgin search sqlite
which had lots of results, including
...
py38-aiosqlite-0.17.0nb1 Async bridge to the standard sqlite3 module
py38-apsw-3.37.0nb2 Python wrapper for SQLite
py38-peewee-3.15.0 Small, expressive ORM for PostgreSQL, MySQL and SQLite
py38-sqlite3-3.8.13nb22 Built-in sqlite support for Python 2.5 and up
py39-aiosqlite-0.17.0nb1 Async bridge to the standard sqlite3 module
py39-apsw-3.37.0nb2 Python wrapper for SQLite
py39-peewee-3.15.0 Small, expressive ORM for PostgreSQL, MySQL and SQLite
py39-sqlite3-3.9.13nb22 Built-in sqlite support for Python 2.5 and up
...
(and other python versions as well). I'm using python 3.9, so py39-sqlite3-3.9.13nb22 was the correct choice in my case. Running
sudo pkgin install py39-sqlite3-3.9.13nb22
fixed the issue for me.

You need to install pysqlite in your python environment:
$ pip install pysqlite

Try copying _sqlite3.so so that Python can find it.
It should be as simple as:
cp /usr/lib64/python2.6/lib-dynload/_sqlite3.so /usr/local/lib/python2.7/
Trust me, try it.

pg_config executable not found on Windows 7 with PostgreSQL installed [duplicate]

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.

Ubuntu Python "No module named paramiko"

So I'm trying to use Paramiko on Ubuntu with Python 2.7, but import paramiko causes this error:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named paramiko
The other questions on this site don't help me since I'm new to Ubuntu.
Here are some important commands that I ran to check stuff:
sudo pip install paramiko
pip install paramiko
sudo apt-get install python-paramiko
Paramiko did "install". These are the only commands I used to "install" paramiko. I'm new to Ubuntu, so if I need to run more commands, lay them on me.
which python
/usr/local/bin/python
python -c "from pprint import pprint; import sys; pprint(sys.path);"
['',
'/usr/local/lib/python27.zip',
'/usr/local/lib/python2.7',
'/usr/local/lib/python2.7/plat-linux2',
'/usr/local/lib/python2.7/lib-tk',
'/usr/local/lib/python2.7/lib-old',
'/usr/local/lib/python2.7/lib-dynload',
'/usr/local/lib/python2.7/site-packages']
In the python interpreter, I ran help("modules") and Paramiko is not in the list.
two paramiko folders are located in usr/local/lib/python2.7/dist-packages.

Short version: You're mixing Ubuntu's packaged version of Python (/usr/bin/python) and a locally built and installed version (/usr/local/bin/python).
Long version:
You used apt-get install python-paramiko to install Ubuntu's official Paramiko package to /usr/lib/python2.7/dist-packages.
You used (I assume) Ubuntu's version of pip, which installs to /usr/local/lib/python2.7/dist-packages. (See here.)
You used a locally built version of Python, and because it's locally built, it uses /usr/local/lib/python2.7 instead of /usr/lib/python2.7, and because it doesn't have Debian/Ubuntu customizations, it doesn't check use dist-packages.
Solution: You should be able to add /usr/local/lib/python2.7/dist-packages to your /usr/local/bin/python's sys.path, but since you're using Ubuntu, it's easiest to let Ubuntu do the work for you:
Use /usr/bin/python instead of a local version.
Use Ubuntu's packages wherever possible (i.e., use apt-get instead of pip).
Use virtualenv for the rest (to keep a clean separation between Ubuntu-packaged and personally installed modules).
I'd go so far as to uninstall the local version of Python and delete /usr/local/lib/python2.7, to ensure that no further mismatches occur. If you don't want to be that drastic, then you can edit your $PATH to put /usr/bin before /usr/local/bin to run the system version of Python by default.

Try downloading the zip file from https://github.com/paramiko/paramiko and running this command in the unzipped directory :
python setup.py install

There are two others methodes for add modules in python :
The first :
Download the package.
Create directory and paste the package in it.
Tap in the terminal :
export PYTHONPATH=$PYTHONPATH:path_of_package
The second :
open python interpreter:
import sys
sys.path.insert(0, "path_of_package")

Try installing only through commands.
Download paramiko package from git using this command: git clone https://github.com/paramiko/paramiko.git
Go to unzipped directory and run export PYTHONPATH=$PYTHONPATH:<path_to_paramiko>
If you find libffi package not found then run this command: sudo apt-get install libffi6 libffi-dev and If you haven't properly installed the header files and static libraries for python dev then run this command: sudo apt-get install python-dev
Enjoy :)

Also, mind the version of python, if the error was reported by python3, then install python3's paramiko.

If you're using Python 3, type the below command
$ sudo -H pip3 install paramiko --ignore-installed

try type pi then tap, this give you this
:$ pi
pic piconv pidstat pinentry-curses ping6
pip3 pivot_root
pic2graph pidof pinentry ping pinky
pip3.6
then you type in whereis pip3
$ whereis pip3
pip3: /usr/local/bin/pip3.6 /usr/local/bin/pip3
xg#xx-ppmaster:/xg/scripts/pyth
$ sudo /usr/local/bin/pip3 install paramiko
This should let you install paramiko
more on python installation
https://danieleriksson.net/2017/02/08/how-to-install-latest-python-on-centos/