What is Python's site-packages directory?

Question

The directory site-packages is mentioned in various Python related articles. What is it? How can I use it?

Semimonthly

Answer 1

site-packages is the target directory of manually built Python packages. When you build and install Python packages from source (using distutils, probably by executing python setup.py install), you will find the installed modules in site-packages by default.

There are standard locations:

• Unix (pure)¹: prefix/lib/pythonX.Y/site-packages
• Unix (non-pure): exec-prefix/lib/pythonX.Y/site-packages
• Windows: prefix\Lib\site-packages

¹ Pure means that the module uses only Python code. Non-pure can contain C/C++ code as well.

site-packages is by default part of the Python search path, so modules installed there can be imported easily afterwards.

---

Useful reading

• Installing Python Modules (for Python 2)
• Installing Python Modules (for Python 3)

Semimonthly

location happened to be /usr/local/lib/python3.6/site-packages on ubuntu – Lichenology

I've seen Gentoo systems with it in lib64! – Deform

does conda or pip install into site-packages, or just manually built packages? – Storied

The really interesting question is: Why this directory? Why not just install to /usr/lib/python3.6? – Mccormick

Is it safe to delete it? I always find that installing packages into a specific environment doesn't work, since it is found unser site-packages. – Airedale

@Airedale I wouldn't do that. I think it's probably better to create the virtual environment and specify --no-site-packages (Which SHOULD be the default but might not be in your situation for various reasons.) virtualenv --no-site-packages --python=/path/to/python/executable/python ENV_DIR_NAME – Capybara

Answer 2

When you use --user option with pip, the package gets installed in user's folder instead of global folder and you won't need to run pip command with admin privileges.

The location of user's packages folder can be found using:

python -m site --user-site

This will print something like:

C:\Users\%USERNAME%\AppData\Roaming\Python\Python35\site-packages

When you don't use --user option with pip, the package gets installed in global folder given by:

python -c "import site; print(site.getsitepackages())"

This will print something like:

['C:\\Program Files\\Anaconda3', 'C:\\Program Files\\Anaconda3\\lib\\site-packages'

Note: Above printed values are for On Windows 10 with Anaconda 4.x installed with defaults.

Friar

Is it safe to delete it? I always find that installing packages into a specific environment doesn't work, since it is found unser site-packages. – Airedale

You shouldn't this directory as it is managed by package manager. – Friar

But what about just deleting specific package inside of site-packages? – Airedale

The --user parameter in python seems valid for Windows but not Linux. In Linux everyone is a user even root I think. – Hyperacidity

Answer 3

site-packages is just the location where Python installs its modules.

There isn't any need to "find it". Python knows where to find it by itself, and this location is always part of the PYTHONPATH (sys.path).

Programmatically you can find it this way:

import sys
site_packages = next(p for p in sys.path if 'site-packages' in p)
print(site_packages)

Output:

'/Users/foo/.envs/env1/lib/python3.11.1/site-packages'

Weekender

Probably easier to import site then site.getsitepackages() – Targett

Not all Python distributions have site-packages, and this will raise StopIteration. For instance, Debian (and Ubuntu) have dist-packages to install their distributed modules. – Bruni

If you use virtualenv and do not inherit global packages then this will always work. I never code without a virtualenv – Weekender

Answer 4

On my CentOS 7.9 Linux (a Red Hat clone) it is found in ~/.local/lib/python3.9/site-packages/ and there isn't any need to include it in the PYTHONPATH variable.

Ethban

I upvoted, unfortunately no other answer gives any hint for per-user python modules. I needed to change path from python3.9 -> python3.11 for newer version. It would be much nicer to get this programmatically though. – Chavaree

Answer 5

Example: let's say we are using python for machine learning, we usually install multiple libraries such as numpy, pandas, tensorflow / torch, etc. When we do "pip install numpy", numpy gets installed. But every wondered where exactly these installed libraries go? This is where site-packages directory comes. site-packages directory stores every third party libraries that we use in our project. The most important thing is, this site-packages directory is not project-dependent. Its environment-dependent, i.e. you can have multiple project run being within a single v.environment and all these projects will have a same site-packages directory that is inside that environment.

Faulty

Answer 6

According to here:

A Python installation has a site-packages directory inside the module directory. This directory is where user installed packages are dropped.

Though it doesn't explain why the word site is chosen, it explains what this directory is meant for.

Tar

That link is from 2009; would you of anything newer, and clear and concise ? – Hoff

@Hoff On the bottom left of that link, it says v:latest. Maybe it is latest. – Tar

"Hitchhiker’s Guide to Packaging" is no longer maintained" ... the bottom of the ".../latest/..." URL page shows copyright 2009. Something on https://packaging.python.org/en/latest/ would be a more recent reference. – Biquarterly