Install python psycopg2 windows — Ваш верный помощник с OS Windows

Psycopg is a PostgreSQL adapter for the Python programming language. It is a
wrapper for the libpq, the official PostgreSQL client library.

Quick Install¶

For most operating systems, the quickest way to install Psycopg is using the
wheel package available on PyPI:

$ pip install psycopg2-binary

This will install a pre-compiled binary version of the module which does not
require the build or runtime prerequisites described below. Make sure to use
an up-to-date version of pip (you can upgrade it using something
like pip install -U pip).

You may then import the psycopg2 package, as usual:

import psycopg2

# Connect to your postgres DB
conn = psycopg2.connect("dbname=test user=postgres")

# Open a cursor to perform database operations
cur = conn.cursor()

# Execute a query
cur.execute("SELECT * FROM my_data")

# Retrieve query results
records = cur.fetchall()

psycopg vs psycopg-binary¶

The psycopg2-binary package is meant for beginners to start playing
with Python and PostgreSQL without the need to meet the build
requirements.

If you are the maintainer of a published package depending on psycopg2
you shouldn’t use psycopg2-binary as a module dependency. For
production use you are advised to use the source distribution.

The binary packages come with their own versions of a few C libraries,
among which libpq and libssl, which will be used regardless of other
libraries available on the client: upgrading the system libraries will not
upgrade the libraries used by psycopg2. Please build psycopg2 from
source if you want to maintain binary upgradeability.

Warning

The psycopg2 wheel package comes packaged, among the others, with its
own libssl binary. This may create conflicts with other extension
modules binding with libssl as well, for instance with the Python
ssl module: in some cases, under concurrency, the interaction between
the two libraries may result in a segfault. In case of doubts you are
advised to use a package built from source.

Change in binary packages between Psycopg 2.7 and 2.8¶

In version 2.7.x, pip install psycopg2 would have tried to install
automatically the binary package of Psycopg. Because of concurrency problems
binary packages have displayed, psycopg2-binary has become a separate
package, and from 2.8 it has become the only way to install the binary
package.

If you are using Psycopg 2.7 and you want to disable the use of wheel binary
packages, relying on the system libraries available on your client, you
can use the pip --no-binary option, e.g.:

$ pip install --no-binary :all: psycopg2

which can be specified in your requirements.txt files too, e.g. use:

psycopg2>=2.7,<2.8 --no-binary psycopg2

to use the last bugfix release of the psycopg2 2.7 package, specifying to
always compile it from source. Of course in this case you will have to meet
the build prerequisites.

Prerequisites¶

The current psycopg2 implementation supports:

Python versions from 3.8 to 3.13
PostgreSQL server versions from 7.4 to 17
PostgreSQL client library version from 9.1

Note

Not all the psycopg2 versions support all the supported Python versions.

Please see the release notes to verify when the support for
a new Python version was added and when the support for an old Python
version was removed.

Build prerequisites¶

The build prerequisites are to be met in order to install Psycopg from source
code, from a source distribution package, GitHub or from PyPI.

Psycopg is a C wrapper around the libpq PostgreSQL client library. To install
it from sources you will need:

A C compiler.
The Python header files. They are usually installed in a package such as
python-dev or python3-dev. A message such as error: Python.h: No
such file or directory is an indication that the Python headers are
missing.
The libpq header files. They are usually installed in a package such as
libpq-dev. If you get an error: libpq-fe.h: No such file or directory
you are missing them.
The pg_config program: it is usually installed by the
libpq-dev package but sometimes it is not in a PATH directory.
Having it in the PATH greatly streamlines the installation, so try
running pg_config --version: if it returns an error or an unexpected
version number then locate the directory containing the pg_config
shipped with the right libpq version (usually
/usr/lib/postgresql/X.Y/bin/) and add it to the PATH:
```
$ export PATH=/usr/lib/postgresql/X.Y/bin/:$PATH
```
You only need pg_config to compile psycopg2, not for its
regular usage.

Once everything is in place it’s just a matter of running the standard:

or, from the directory containing the source code:

$ python setup.py build
$ python setup.py install

Runtime requirements¶

Unless you compile psycopg2 as a static library, or you install it from a
self-contained wheel package, it will need the libpq library at runtime
(usually distributed in a libpq.so or libpq.dll file). psycopg2
relies on the host OS to find the library if the library is installed in a
standard location there is usually no problem; if the library is in a
non-standard location you will have to tell Psycopg how to find it,
which is OS-dependent (for instance setting a suitable
LD_LIBRARY_PATH on Linux).

Note

The libpq header files used to compile psycopg2 should match the
version of the library linked at runtime. If you get errors about missing
or mismatching libraries when importing psycopg2 check (e.g. using
ldd) if the module psycopg2/_psycopg.so is linked to the
right libpq.so.

Note

Whatever version of libpq psycopg2 is compiled with, it will be
possible to connect to PostgreSQL servers of any supported version: just
install the most recent libpq version or the most practical, without
trying to match it to the version of the PostgreSQL server you will have
to connect to.

Non-standard builds¶

If you have less standard requirements such as:

creating a debug build,
using pg_config not in the PATH,

then take a look at the setup.cfg file.

Some of the options available in setup.cfg are also available as command
line arguments of the build_ext sub-command. For instance you can specify
an alternate pg_config location using:

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

Use python setup.py build_ext --help to get a list of the options
supported.

Creating a debug build¶

In case of problems, Psycopg can be configured to emit detailed debug
messages, which can be very useful for diagnostics and to report a bug. In
order to create a debug package:

Download and unpack the Psycopg source package (the .tar.gz
package).
Edit the setup.cfg file adding the PSYCOPG_DEBUG flag to the
define option.
Compile and install the package.
Set the PSYCOPG_DEBUG environment variable:

Run your program (making sure that the psycopg2 package imported is the
one you just compiled and not e.g. the system one): you will have a copious
stream of informations printed on stderr.

Non-standard Python Implementation¶

The psycopg2 package is the current mature implementation of the adapter: it
is a C extension and as such it is only compatible with CPython. If you want
to use Psycopg on a different Python implementation (PyPy, Jython, IronPython)
there is a couple of alternative:

a Ctypes port, but it is not as mature as the C implementation yet
and it is not as feature-complete;
a CFFI port which is currently more used and reported more efficient on
PyPy, but please be careful of its version numbers because they are not
aligned to the official psycopg2 ones and some features may differ.

Running the test suite¶

Once psycopg2 is installed you can run the test suite to verify it is
working correctly. From the source directory, you can run:

$ python -c "import tests; tests.unittest.main(defaultTest='tests.test_suite')" --verbose

The tests run against a database called psycopg2_test on UNIX socket and
the standard port. You can configure a different database to run the test by
setting the environment variables:

PSYCOPG2_TESTDB
PSYCOPG2_TESTDB_HOST
PSYCOPG2_TESTDB_PORT
PSYCOPG2_TESTDB_USER

The database should already exist before running the tests.

If you still have problems¶

Try the following. In order:

Read again the Build prerequisites.
Read the FAQ.
Google for psycopg2 your error message. Especially useful the week
after the release of a new OS X version.
Write to the Mailing List.
If you think that you have discovered a bug, test failure or missing feature
please raise a ticket in the bug tracker.
Complain on your blog or on Twitter that psycopg2 is the worst package
ever and about the quality time you have wasted figuring out the correct
ARCHFLAGS. Especially useful from the Starbucks near you.

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Psycopg is the most popular PostgreSQL database adapter for the Python
programming language. Its main features are the complete implementation of
the Python DB API 2.0 specification and the thread safety (several threads can
share the same connection). It was designed for heavily multi-threaded
applications that create and destroy lots of cursors and make a large number
of concurrent “INSERT”s or “UPDATE”s.

Psycopg 2 is mostly implemented in C as a libpq wrapper, resulting in being
both efficient and secure. It features client-side and server-side cursors,
asynchronous communication and notifications, “COPY TO/COPY FROM” support.
Many Python types are supported out-of-the-box and adapted to matching
PostgreSQL data types; adaptation can be extended and customized thanks to a
flexible objects adaptation system.

Psycopg 2 is both Unicode and Python 3 friendly.

Documentation

Documentation is included in the doc directory and is available online.

For any other resource (source code repository, bug tracker, mailing list)
please check the project homepage.

Installation

Building Psycopg requires a few prerequisites (a C compiler, some development
packages): please check the install and the faq documents in the doc dir
or online for the details.

If prerequisites are met, you can install psycopg like any other Python
package, using pip to download it from PyPI:

$ pip install psycopg2

or using setup.py if you have downloaded the source package locally:

$ python setup.py build
$ sudo python setup.py install

You can also obtain a stand-alone package, not requiring a compiler or
external libraries, by installing the psycopg2-binary package from PyPI:

$ pip install psycopg2-binary

The binary package is a practical choice for development and testing but in
production it is advised to use the package built from sources.

Linux/OSX:
Windows:

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Пройдите тест, узнайте какой профессии подходите

Установка библиотеки psycopg2 в Python может вызвать определенные трудности для новичков. Это связано с тем, что процесс установки включает в себя работу

Установка библиотеки psycopg2 в Python может вызвать определенные трудности для новичков. Это связано с тем, что процесс установки включает в себя работу с виртуальной средой и использование инструмента pip. В рамках данной статьи рассмотрим типичную проблему, которую можно встретить при установке psycopg2.

Примером такой проблемы может служить ситуация, когда при попытке установки psycopg2 через pip возникает сообщение об ошибке, указывающее на отсутствие исполняемого файла pg_config. Это происходит из-за того, что pip не может найти необходимые для установки psycopg2 файлы.

pip install psycopg2

В результате выполнения этой команды может появиться сообщение об ошибке, в котором говорится, что исполняемый файл pg_config не найден.

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'.

Это означает, что pip не может найти файл pgconfig, который необходим для установки psycopg2. Для решения этой проблемы можно прописать путь к исполняемому файлу pgconfig в переменной PATH или указать полный путь к исполняемому файлу при установке psycopg2.

Для того чтобы указать путь к файлу pg_config в переменной PATH, необходимо выполнить следующую команду в консоли:

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

Для указания пути к файлу pg_config при установке psycopg2, можно использовать следующую команду:

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

Эта команда подскажет pip, где именно находится файл pg_config.

Таким образом, при возникновении проблемы с установкой psycopg2 через pip, можно исправить ситуацию, указав путь к файлу pg_config. Это позволит успешно установить библиотеку и продолжить работу с Python.

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Last Updated :
03 Oct, 2024

When working with PostgreSQL databases in Python, we often need to use the psycopg2 library. It’s a popular PostgreSQL adapter for Python, making it easy to interact with PostgreSQL databases. In this article, we will learn how to install psycopg2 in Visual Studio Code (VS Code) on our system.

Step 1 — Set Up Python in VS Code

Note: Before we install psycopg2, we need to ensure that Python is installed on our system and set up in VS Code.
If you already have Python installed, you can skip this step.

Download Python:

Go to the official Python website and download the latest version of Python.

Click on Download Button

Next Run the installer. Make sure to check the box that says «Add Python to PATH» during the installation.

Step 2 — Install VS Code:

We can download VS Code from the official VS Code website and install it.

Download as per your system

Open a Terminal in VS Code

To install psycopg2, we need to use the terminal in VS Code.

Before that, let’s create a virtual environment for our Python projects to keep dependencies isolated.

In the terminal, navigate to the project folder using cd project_directory. Then, run the following command to create a virtual environment:

python -m venv venv

Activate Virtual Environment,

.\venv\Scripts\activate  #for windows

source venv/bin/activate #for macOS/Linux

Step 3: Install psycopg2

Now that our environment is ready, we can install psycopg2 using pip.

pip install psycopg2

Output:

Succesfully Installed

Step 4 — Verify the Installation

First create a New Python File: To test whether the installation was successful, we can check the version of psycopg2 using the following command:

python -c "import psycopg2; print (psycopg2.__version__)"

Check Psycopg2 Version

The -c flag allows us to run Python code directly from the command line without needing to write it into a script file.

Other way to test the installation:

In VS Code, create a new Python file (e.g., test_psycopg2.py) and add the following code.

Python



import psycopg2

print(psycopg2.__version__)

Upon running the python file using python -m test_psycopg2.py, if we get the desired output meaning that the installation was successful.

Output:

Check Psycopg2 Version

Troubleshooting Common Issues

Error: «No module named ‘psycopg2′» this error usually means that the psycopg2 library isn’t installed in the current environment. Ensure whether the correct virtual environment is activated and run pip install psycopg2 again.
If we get build errors on Windows, we can fix this by installing the psycopg2-binary package as mentioned earlier.
If VS Code isn’t recognizing our Python installation, we can verify that the correct Python interpreter is selected in VS Code. We can change it by clicking on the Python version in the bottom left corner of VS Code and selecting the correct interpreter.

Conclusion

Installing psycopg2 in Visual Studio Code is a simple process that allows us to easily interact with PostgreSQL databases using Python. By setting up your environment correctly and following the steps outlined in this article, we can ensure that psycopg2 is installed and functioning properly. Whether we’re working on a small project or a large-scale application, having psycopg2 integrated on our system will streamline our database operations and improve our workflow.

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