Commit 7ae2a4a7 authored by Guido van Rossum's avatar Guido van Rossum

Auto-install on first import.

Added quick reference.
parent 53d6863d
"""New import scheme with package support.
Quick Reference
---------------
- To enable package support, execute "import ni" before importing any
packages. Importing this module automatically installs the relevant
import hooks.
- To create a package named spam containing sub-modules ham, bacon and
eggs, create a directory spam somewhere on Python's module search
path (i.e. spam's parent directory must be one of the directories in
sys.path or $PYTHONPATH); then create files ham.py, bacon.py and
eggs.py inside spam.
- To import module ham from package spam and use function hamneggs()
from that module, you can either do
import spam.ham # *not* "import spam" !!!
spam.ham.hamneggs()
or
from spam import ham
ham.hamneggs()
or
from spam.ham import hamneggs
hamneggs()
- Importing just "spam" does not do what you expect: it creates an
empty package named spam if one does not already exist, but it does
not import spam's submodules. The only submodule that is guaranteed
to be imported is spam.__init__, if it exists. Note that
spam.__init__ is a submodule of package spam. It can reference to
spam's namespace via the '__.' prefix, for instance
__.spam_inited = 1 # Set a package-level variable
Theory of Operation
-------------------
A Package is a module that can contain other modules. Packages can be
nested. Package introduce dotted names for modules, like P.Q.M, which
could correspond to a file P/Q/M.py found somewhere on sys.path. It
......@@ -388,3 +431,5 @@ def testproper():
if __name__ == '__main__':
test()
else:
install()
"""New import scheme with package support.
Quick Reference
---------------
- To enable package support, execute "import ni" before importing any
packages. Importing this module automatically installs the relevant
import hooks.
- To create a package named spam containing sub-modules ham, bacon and
eggs, create a directory spam somewhere on Python's module search
path (i.e. spam's parent directory must be one of the directories in
sys.path or $PYTHONPATH); then create files ham.py, bacon.py and
eggs.py inside spam.
- To import module ham from package spam and use function hamneggs()
from that module, you can either do
import spam.ham # *not* "import spam" !!!
spam.ham.hamneggs()
or
from spam import ham
ham.hamneggs()
or
from spam.ham import hamneggs
hamneggs()
- Importing just "spam" does not do what you expect: it creates an
empty package named spam if one does not already exist, but it does
not import spam's submodules. The only submodule that is guaranteed
to be imported is spam.__init__, if it exists. Note that
spam.__init__ is a submodule of package spam. It can reference to
spam's namespace via the '__.' prefix, for instance
__.spam_inited = 1 # Set a package-level variable
Theory of Operation
-------------------
A Package is a module that can contain other modules. Packages can be
nested. Package introduce dotted names for modules, like P.Q.M, which
could correspond to a file P/Q/M.py found somewhere on sys.path. It
......@@ -388,3 +431,5 @@ def testproper():
if __name__ == '__main__':
test()
else:
install()
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