Re: __init__.py in packages
Le Wed, 08 Jun 2005 10:34:38 -0500, Gary Wilson Jr a écrit : I'm creating a python package foo. What is intended use for __init__.py files? Well, I found this: http://www.python.org/doc/essays/packages.html From what I can gather it is for initialization of the package when doing an import, but I would really like to see an example or situation that makes good use of the __init__.py file. Looking at the distutils __init__.py file, it only defines things like __version__. However, looking at the logging __init__.py file, it is a 1196-line monster with functions and classes defined throughout. What is the RightThing? The RightThing is to not name your package foo :-) from foo import MyClass Or is is better if I were to put these classes and/or functions in foo/core.py? Whereby I would do something like: from foo.core import MyClass Naming matters. First find good names, second write down good docstrings. In case you have difficulties to find good names, read How to write unmaintainable code and you end up with : from Mary.Poppins import Pinochio # the electromagnetics simulator. -- Cent fois sur le métier, remettez votre ouvrage. Polissez-le et le repolissez Boileau Despréaux. -- http://mail.python.org/mailman/listinfo/python-list
Re: __init__.py in packages
Gary Wilson Jr napisa(a): What is intended use for __init__.py files? Well, I found this: http://www.python.org/doc/essays/packages.html From what I can gather it is for initialization of the package when doing an import, but I would really like to see an example or situation that makes good use of the __init__.py file. Looking at the distutils __init__.py file, it only defines things like __version__. However, looking at the logging __init__.py file, it is a 1196-line monster with functions and classes defined throughout. What is the RightThing? I don't know The Right Thing, I just use __init__.py as namespace shortcut -- everything you define there (functions, classes, names), will be available at module level, not deeper. Should I only define things in __init__.py that need to be defined when importing a subpackage and/or module of package foo? Is it ok for me to define classes in foo/__init__.py? Whereby I could do something like: from foo import MyClass Or is is better if I were to put these classes and/or functions in foo/core.py? Whereby I would do something like: from foo.core import MyClass It's mostly a matter of taste. And logic. -- Jarek Zgoda http://jpa.berlios.de/ | http://www.zgodowie.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: __init__.py in packages
Gary Wilson Jr wrote: I would really like to see an example or situation that makes good use of the __init__.py file. I've attached a non-trivial example, from my PyGUI package. It uses some trickery to switch in one of a number of subdirectories of platform specific code, and then imports a bunch of names from submodules into the top-level package, so the user can pretend he's just using a single top-level module, e.g. from GUI import Window even though Window is actually defined in some submodule. This is a rather extreme example, though -- most __init__.py files are much simpler! -- Greg Ewing, Computer Science Dept, University of Canterbury, Christchurch, New Zealand http://www.cosc.canterbury.ac.nz/~greg _versions = [ (Carbon, Mac), (gtk, Gtk), ] from os import environ as _env _platdir = _env.get(PYGUI_IMPLEMENTATION) if not _platdir: for _testmod, _platdir in _versions: try: __import__(_testmod) break except ImportError: continue else: raise ImportError(Unable to find an implementation of PyGUI for this installation) print PyGUI: Using implementation:, _platdir from os.path import join as _join _here = __path__[0] __path__.append(_join(_here, _platdir)) __path__.append(_join(_here, Generic)) from Version import version from Actions import Action from AlertFunctions import alert, alert2, alert3, \ stop_alert, note_alert, confirm, ask, confirm_or_cancel, ask_or_cancel from Applications import Application, application from Buttons import Button from CheckBoxes import CheckBox from Colors import Color, rgb from Components import Component from Dialogs import Dialog from Documents import Document from Events import Event from Exceptions import Cancel from FileDialogs import request_old_file, request_new_file from Files import FileRef, DirRef from Fonts import Font from Containers import Frame from Images import Image from Labels import Label from Menus import Menu from MessageHandlers import MessageHandler from ModalDialogs import ModalDialog from Models import Model from Pixmaps import Pixmap from Properties import Properties, overridable_property from RadioButtons import RadioButton from RadioGroups import RadioGroup from ScrollBars import ScrollBar from ScrollFrames import ScrollFrame import StdColors import StdFonts from Tasks import Task from TextFields import TextField ##from TextModels import TextModel ##from TextViews import TextView from Views import View from Windows import Window -- http://mail.python.org/mailman/listinfo/python-list
