大约有 13,310 项符合查询结果(耗时:0.0225秒) [XML]

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Calling class staticmethod within the class body?

... staticmethod objects apparently have a __func__ attribute storing the original raw function (makes sense that they had to). So this will work: class Klass(object): @staticmethod # use as decorator def stat_func(): return 42 _ANS = stat_func...
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Python __call__ special method practical example

I know that __call__ method in a class is triggered when the instance of a class is called. However, I have no idea when I can use this special method, because one can simply create a new method and perform the same operation done in __call__ method and instead of calling the instance, you can c...
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Is there a simple, elegant way to define singletons? [duplicate]

...se the Instance method. Here's an example: @Singleton class Foo: def __init__(self): print 'Foo created' f = Foo() # Error, this isn't how you get the instance of a singleton f = Foo.instance() # Good. Being explicit is in line with the Python Zen g = Foo.instance() # Returns already ...
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How do I initialize the base (super) class?

... and invoke their base class through super(), e.g. class X(object): def __init__(self, x): pass def doit(self, bar): pass class Y(X): def __init__(self): super(Y, self).__init__(123) def doit(self, foo): return super(Y, self).doit(foo) Because python knows about old- an...
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Solving “Who owns the Zebra” programmatically?

...all drink different drinks. # They all smoke different cigarettes. for vars_ in (colors, nationalities, pets, drinks, cigarettes): problem.addConstraint(AllDifferentConstraint(), vars_) # In the middle house they drink milk. #NOTE: interpret "middle" in a numerical sense (not geometrical) probl...
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What are the differences between NP, NP-Complete and NP-Hard?

...njunction (ANDs) of 3-clause disjunctions (ORs), statements of the form (x_v11 OR x_v21 OR x_v31) AND (x_v12 OR x_v22 OR x_v32) AND ... AND (x_v1n OR x_v2n OR x_v3n) where each x_vij is a boolean variable or the negation of a variable from a finite predefined list (x_1, x...
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Checking if an instance's class implements an interface?

... As therefromhere points out, you can use class_implements(). Just as with Reflection, this allows you to specify the class name as a string and doesn't require an instance of the class: interface IInterface { } class TheClass implements IInterface { } $interfaces = cl...
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STL中map容器使用自定义key类型报错详解 - C/C++ - 清泛网 - 专注C/C++及内核技术

...定义一个结构体来试试:[cpp]view plaincopystructa{char*pName;intm_a;} 引言 STL的map容器中,key的类型是不是随意的呢? 实践 编写测试代码 定义一个结构体来试试: struct a { char* pName; int m_a; }; ... map<a, int> mp; a ...
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How to make a class property? [duplicate]

...re's how I would do this: class ClassPropertyDescriptor(object): def __init__(self, fget, fset=None): self.fget = fget self.fset = fset def __get__(self, obj, klass=None): if klass is None: klass = type(obj) return self.fget.__get__(obj, klass)(...
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List all base classes in a hierarchy of given class?

...gt; &gt;&gt;&gt; import inspect &gt;&gt;&gt; inspect.getmro(B) (&lt;class '__main__.B'&gt;, &lt;class '__main__.A'&gt;, &lt;type 'object'&gt;) share | improve this answer | ...