ref: 1fe3143e4c43ce2c74e0cfdd70b1bd556bbb9e1b
dir: /sys/src/cmd/python/Doc/lib/libni.tex/
\section{\module{ni} --- None} \declaremodule{standard}{ni} \modulesynopsis{None} \strong{Warning: This module is obsolete.} As of Python 1.5a4, package support (with different semantics for \code{__init__} and no support for \code{__domain__} or \code{__}) is built in the interpreter. The ni module is retained only for backward compatibility. As of Python 1.5b2, it has been renamed to \code{ni1}; if you really need it, you can use \code{import ni1}, but the recommended approach is to rely on the built-in package support, converting existing packages if needed. Note that mixing \code{ni} and the built-in package support doesn't work: once you import \code{ni}, all packages use it. The \code{ni} module defines a new importing scheme, which supports packages containing several Python modules. To enable package support, execute \code{import ni} before importing any packages. Importing this module automatically installs the relevant import hooks. There are no publicly-usable functions or variables in the \code{ni} module. To create a package named \code{spam} containing sub-modules \code{ham}, \code{bacon} and \code{eggs}, create a directory \file{spam} somewhere on Python's module search path, as given in \code{sys.path}. Then, create files called \file{ham.py}, \file{bacon.py} and \file{eggs.py} inside \file{spam}. To import module \code{ham} from package \code{spam} and use function \code{hamneggs()} from that module, you can use any of the following possibilities: \begin{verbatim} import spam.ham # *not* "import spam" !!! spam.ham.hamneggs() \end{verbatim} % \begin{verbatim} from spam import ham ham.hamneggs() \end{verbatim} % \begin{verbatim} from spam.ham import hamneggs hamneggs() \end{verbatim} % \code{import spam} creates an empty package named \code{spam} if one does not already exist, but it does \emph{not} automatically import \code{spam}'s submodules. The only submodule that is guaranteed to be imported is \code{spam.__init__}, if it exists; it would be in a file named \file{__init__.py} in the \file{spam} directory. Note that \code{spam.__init__} is a submodule of package spam. It can refer to spam's namespace as \code{__} (two underscores): \begin{verbatim} __.spam_inited = 1 # Set a package-level variable \end{verbatim} % Additional initialization code (setting up variables, importing other submodules) can be performed in \file{spam/__init__.py}.