sitepackages

Site-packages is the directory in a Python installation where third-party packages are installed and made available for import. It is part of the interpreter’s search path, so modules and packages placed there can be imported by Python code without special configuration.

Location and layout vary by platform and Python version. Commonly, the directory is named site-packages and resides under lib/pythonX.Y/site-packages (for example, lib/python3.11/site-packages on Unix-like systems) or under Lib\site-packages on Windows. Some operating systems and distributions also use a separate dist-packages location for system-packaged Python components, such as /usr/lib/pythonX.Y/dist-packages, in addition to or instead of site-packages.

There can be multiple site-packages directories in a Python environment. A standard global installation uses the system-wide site-packages, while virtual environments (venvs) create their own isolated site-packages directory so installed packages do not affect the global Python installation. In addition, Python supports per-user installations via the --user option, which places packages in a user-specific site-packages directory that participates in module discovery.

Python discovers site-packages at startup through the site module, which appends relevant paths to sys.path so that imported packages can be located. Variables such as PYTHONPATH or the per-user PYTHONUSERBASE can influence the search paths.

Pip and similar packaging tools install packages into site-packages by default. Understanding site-packages is important for managing dependencies, creating reproducible environments, and troubleshooting import errors.