pycentral

pycentral subcommand [arguments]

subcommand
    The specific action to perform. pycentral operates using various subcommands, each executing a distinct task related to Python module management within a Debian package context. Common subcommands include compile, install, register, unregister, and clean.

compile
    Instructs pycentral to byte-compile Python source files (.py) into bytecode files (.pyc and .pyo) within a specified path or package context, improving module load times.

install module
    Used during package installation to process and register a Python module or package with the system. This often involves byte-compilation and updating internal module registries.

register module
    Registers a specific Python module with the system's central registry, making it discoverable by the Python interpreter and other applications. This is typically part of the package installation process.

unregister module
    Unregisters a Python module from the system's central registry. This subcommand is primarily used during package removal to clean up module registrations.

clean
    Removes byte-compiled files (.pyc, .pyo) and other temporary data generated by pycentral, often used in the package clean-up phase.

--version
    Displays the version information for the pycentral utility.

--help
    Shows a help message, detailing the command's usage and listing available subcommands and their basic functions.

pycentral was a utility included in the python-central Debian package, primarily used in the Debian/Ubuntu packaging ecosystem. Its main purpose was to assist maintainers in handling Python modules during package installation and removal. It provided functionalities for byte-compiling Python source files (.py to .pyc and .pyo), registering installed modules with the system, and managing dependencies. While not a user-facing command for everyday system administration, pycentral played a crucial role in ensuring that Python packages were correctly integrated into the system, making their modules discoverable by the Python interpreter.

Over time, its functionality has largely been superseded by newer, more robust tools like dh_python2 and dh_python3 (part of debhelper), which streamline Python package building and comply with modern Python packaging standards, including PEP 394 and PEP 397 for Python 2 and 3 compatibility. As a result, pycentral is now considered deprecated and is rarely used in modern Debian/Ubuntu packages. Its design aimed to centralize Python module management, hence the "central" in its name.

The pycentral utility is considered deprecated and is rarely used in modern Debian/Ubuntu packaging. Its functionalities have been superseded by newer tools like dh_python2 and dh_python3 from the debhelper suite. Using pycentral in new projects or attempting to manage Python environments directly with it is not recommended, as it can lead to conflicts with standard Python packaging practices (e.g., pip, virtualenv) and may not be compatible with newer Python versions or distribution layouts. It was specifically designed for the Debian packaging system's needs, not for general Python development workflows.

pycentral was designed exclusively for the Debian/Ubuntu packaging system. It was typically invoked by debian/rules build scripts to perform actions like byte-compiling Python source files and registering module paths with a central registry that the system's Python interpreter could use. It was not intended for direct use by end-users for managing their Python environments or installing Python packages outside the distribution's package manager (apt/dpkg).

One of the primary functions of pycentral was to handle the byte-compilation of Python source files. When Python code is executed, it is first compiled into bytecode, which is then run by the Python Virtual Machine. pycentral automated the creation of .pyc (compiled bytecode) and .pyo (optimized bytecode) files during package installation, which could potentially speed up subsequent module imports by avoiding recompilation on each run.

pycentral was introduced as part of the python-central package in the Debian GNU/Linux distribution. Its development aimed to provide a standardized, centralized mechanism for Debian packages to manage Python modules, including byte-compilation and registration, ensuring consistency across the system. It was a key component for Python package maintainers during the Debian Etch, Lenny, and Squeeze eras.

However, with the evolution of Python packaging standards (like PEP 394 for Python 2/3 compatibility) and the introduction of more flexible and robust build tools within the debhelper framework (specifically dh_python2 and dh_python3), pycentral's approach became less suitable for modern packaging needs. Consequently, its use has been actively discouraged and largely replaced since Debian 7 (Wheezy) and Ubuntu 12.04 (Precise Pangolin), making it a historical artifact in the Debian packaging system rather than a current tool.

dh_python2(1), dh_python3(1), dpkg(1), apt(8), python(1)