大约有 13,700 项符合查询结果（耗时：0.0349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?
...
Can someone explain __all__ in Python?
I have been using Python more and more, and I keep seeing the variable __all__ set in different __init__.py files. Can someone explain what this does?
...
Overloading Macro on Number of Arguments
...
Simple as:
#define GET_MACRO(_1,_2,_3,NAME,...) NAME
#define FOO(...) GET_MACRO(__VA_ARGS__, FOO3, FOO2)(__VA_ARGS__)
So if you have these macros:
FOO(World, !) # expands to FOO2(World, !)
FOO(foo,bar,baz) # expands to FOO3(foo,bar...
Elegant ways to support equivalence (“equality”) in Python classes
... and != operators. In Python, this is made possible by implementing the __eq__ and __ne__ special methods, respectively. The easiest way I've found to do this is the following method:
...
What is the most efficient/elegant way to parse a flat table into a tree?
...e Pitfalls of Database Programming.
CREATE TABLE ClosureTable (
ancestor_id INT NOT NULL REFERENCES FlatTable(id),
descendant_id INT NOT NULL REFERENCES FlatTable(id),
PRIMARY KEY (ancestor_id, descendant_id)
);
Store all paths in the Closure Table, where there is a direct ancestry from o...
Getting attributes of a class
...gt;> inspect.getmembers(MyClass, lambda a:not(inspect.isroutine(a)))
[('__class__', type),
('__dict__',
<dictproxy {'__dict__': <attribute '__dict__' of 'MyClass' objects>,
'__doc__': None,
'__module__': '__main__',
'__weakref__': <attribute '__weakref__' of 'MyClass' obje...
What is the difference between __init__ and __call__?
I want to know the difference between __init__ and __call__ methods.
13 Answers
...
In Python, how do I determine if an object is iterable?
...'ve lately started to get more and more annoyed by objects which only have __getitem__ being considered iterable. There are valid reasons to have __getitem__ in a non-iterable object and with them the above code doesn't work well. As a real life example we can use Faker. The above code reports it be...
What does if __name__ == “__main__”: do?
Given the following code, what does the if __name__ == "__main__": do?
33 Answers
33...
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
...