大约有 43,000 项符合查询结果（耗时：0.0483秒） [XML]
Difference between __getattr__ vs __getattribute__
I am trying to understand when to use __getattr__ or __getattribute__ . The documentation mentions __getattribute__ applies to new-style classes. What are new-style classes?
...
How do I create a namespace package in Python?
...
TL;DR:
On Python 3.3 you don't have to do anything, just don't put any __init__.py in your namespace package directories and it will just work. On pre-3.3, choose the pkgutil.extend_path() solution over the pkg_resources.declare_namespace() one, because it's future-proof and already compatible w...
How do I implement __getattribute__ without an infinite recursion error?
...n a class, but return all others normally. How do I accomplish this with __getattribute__ ?
6 Answers
...
How do I correctly clean up a Python object?
__del__(self) above fails with an AttributeError exception. I understand Python doesn't guarantee the existence of "global variables" (member data in this context?) when __del__() is invoked. If that is the case and this is the reason for the exception, how do I make sure the object destructs...
Is it possible to make abstract classes in Python?
...
# Python 2
from abc import ABCMeta, abstractmethod
class Abstract:
__metaclass__ = ABCMeta
@abstractmethod
def foo(self):
pass
Whichever way you use, you won't be able to instantiate an abstract class that has abstract methods, but will be able to instantiate a subclass th...
How to retrieve a module's path?
...
import a_module
print(a_module.__file__)
Will actually give you the path to the .pyc file that was loaded, at least on Mac OS X. So I guess you can do:
import os
path = os.path.abspath(a_module.__file__)
You can also try:
path ...
How do I check OS with a preprocessor directive?
...ecks. Here are a few of them, with links to where they're found:
Windows
_WIN32 Both 32 bit and 64 bit
_WIN64 64 bit only
Unix (Linux, *BSD, Mac OS X)
See this related question on some of the pitfalls of using this check.
unix
__unix
__unix__
Mac OS X
__APPLE__
__MACH__
Both are de...
How do I get the full path of the current file's directory?
...3
For the directory of the script being run:
import pathlib
pathlib.Path(__file__).parent.absolute()
For the current working directory:
import pathlib
pathlib.Path().absolute()
Python 2 and 3
For the directory of the script being run:
import os
os.path.dirname(os.path.abspath(__file__))
I...
How to use a dot “.” to access members of dictionary?
...ope to help you:
class Map(dict):
"""
Example:
m = Map({'first_name': 'Eduardo'}, last_name='Pool', age=24, sports=['Soccer'])
"""
def __init__(self, *args, **kwargs):
super(Map, self).__init__(*args, **kwargs)
for arg in args:
if isinstance(arg, dict...
Ruby send vs __send__
I understand the concept of some_instance.send but I'm trying to figure out why you can call this both ways. The Ruby Koans imply that there is some reason beyond providing lots of different ways to do the same thing. Here are the two examples of usage:
...