大约有 40,000 项符合查询结果（耗时：0.0269秒） [XML]
List all base classes in a hierarchy of given class?
...ass Foo (whether it is a new-style class or not), how do you generate all the base classes - anywhere in the inheritance hierarchy - it issubclass of?
...
What is the most efficient/elegant way to parse a flat table into a tree?
...
Now that MySQL 8.0 supports recursive queries, we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentI...
How to save all the variables in the current python session?
I want to save all the variables in my current python environment. It seems one option is to use the 'pickle' module. However, I don't want to do this for 2 reasons:
...
Viewing all defined variables [duplicate]
...ython shell. What I want to have is Matlab style listout where you can see all the variables that have been defined up to a point (so I know which names I've used, their values and such).
...
Relative imports in Python 2.7
... not determine what package Python thinks it is in. That depends, additionally, on how you load the file into Python (by running or by importing).
There are two ways to load a Python file: as the top-level script, or as a
module. A file is loaded as the top-level script if you execute it directl...
How does __proto__ differ from constructor.prototype?
...
I've been trying to wrap my head around this recently and finally came up with this "map" that I think sheds full light over the matter
http://i.stack.imgur.com/KFzI3.png
I know I'm not the first one making this up but it was more interesting figuring it out that finding it :-). An...
How to initialize all members of an array to the same value?
... array in C (not C++ if that makes a difference). I want to initialize all members of the same value.
23 Answers
...
Why is the order in dictionaries and sets arbitrary?
...der:
>>> {'bar': None, 'foo': None}
{'foo': None, 'bar': None}
All slots except 3 and 4 are empty, looping over the table first lists slot 3, then slot 4, so 'foo' is listed before 'bar'.
bar and baz, however, have hash values that are exactly 8 apart and thus map to the exact same slot...
Solving “Who owns the Zebra” programmatically?
...ution in Python based on constraint-programming:
from constraint import AllDifferentConstraint, InSetConstraint, Problem
# variables
colors = "blue red green white yellow".split()
nationalities = "Norwegian German Dane Swede English".split()
pets = "birds dog cats horse zebra".sp...
Get all object attributes in Python? [duplicate]
Is there a way to get all attributes/methods/fields/etc. of an object in Python?
4 Answers
...