python terminology on classes
in [Python]
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From: Peng Yu on 26 Jul 2010 17:52 Hi I'm still kind of confused about the terminology on classes in python. Could you please let me know what the equivalent terms for the following C++ terms? constructor destructor member function member variable virtual member function function I think that C++ "function" is equivalent to python "function" and C++ "member function" is equivalent to python "method". But I couldn't locate where the original definitions of the corresponding python terms in the manual as these term appear many times. Could you please point me where to look for the definition of these python corresponding terms? -- Regards, Peng
From: Thomas Jollans on 26 Jul 2010 19:15 On 07/26/2010 11:52 PM, Peng Yu wrote: > Hi > > I'm still kind of confused about the terminology on classes in python. > > Could you please let me know what the equivalent terms for the > following C++ terms? > > constructor constructor. This consists of the class constructor method, __new__, and of the instance initialization method, __init__ In practice, __init__ is really "the constructor". http://docs.python.org/py3k/reference/datamodel.html#object.__new__ > destructor destructor. http://docs.python.org/py3k/reference/datamodel.html#object.__del__ > member function method. Look for "instance method" below <URL:http://docs.python.org/py3k/reference/datamodel.html#the-standard-type-hierarchy> > member variable attribute, instance attribute, instance variable. > virtual member function all methods are virtual. > function function. > I think that C++ "function" is equivalent to python "function" and C++ > "member function" is equivalent to python "method". But I couldn't > locate where the original definitions of the corresponding python > terms in the manual as these term appear many times. Could you please > point me where to look for the definition of these python > corresponding terms? http://docs.python.org/py3k/reference/datamodel.html should answer all your questions.
From: Rhodri James on 26 Jul 2010 19:29 On Mon, 26 Jul 2010 22:52:06 +0100, Peng Yu <pengyu.ut(a)gmail.com> wrote: > Hi > > I'm still kind of confused about the terminology on classes in python. > > Could you please let me know what the equivalent terms for the > following C++ terms? Seriously, we can't keep doing your thinking for you. The answers to all your questions are section 9 of the tutorial. -- Rhodri James *-* Wildebeeste Herder to the Masses
From: Tim Chase on 26 Jul 2010 19:31 On 07/26/10 18:15, Thomas Jollans wrote: >> destructor > > http://docs.python.org/py3k/reference/datamodel.html#object.__del__ One small caveat -- IIRC, in Java/C++ the destructor is guaranteed to be called with a certain amount of context. I find Python's __del__ almost useless since things it may rely upon can arbitrarily be destroyed before the __del__ is called. -tkc
From: Steven D'Aprano on 26 Jul 2010 20:04
On Mon, 26 Jul 2010 16:52:06 -0500, Peng Yu wrote: > Could you please let me know what the equivalent terms for the following > C++ terms? > > constructor > destructor > member function > member variable > virtual member function > function (1) Python new-style classes have a constructor __new__ and an initialiser __init__. Some people describe both as constructors, but that's strictly incorrect because the instance has already been constructed by the time __init__ is called. (Old-style classes don't have __new__, only __init__.) (2) Python destructors are called __del__ , but you shouldn't use them unless you really know what you are doing. (3) "Member functions" are methods. (4) "Member variables" are attributes. If you have to distinguish between attributes which live on the instance from one that lives on the class, "instance attribute" and "class attribute". (5) I believe that all methods in Python are virtual. (6) Function. > I think that C++ "function" is equivalent to python "function" and C++ > "member function" is equivalent to python "method". But I couldn't > locate where the original definitions of the corresponding python terms > in the manual as these term appear many times. Could you please point me > where to look for the definition of these python corresponding terms? I believe you are right, but I can't find a definition of C++ "member function" that makes sense. Can you please point me where to look for the definition of these C++ terms? I don't believe the Python Language Reference explicitly defines terms such as "attribute" and "method", but the tutorial may help: http://docs.python.org/tutorial/classes.html Quote: In C++ terminology, all class members (including the data members) are public, and all member functions are virtual. Note: although the docs occasionally use the term "members" for attributes, it is considered more standard to use "attribute" or "method" unless discussing data types defined at the C layer. -- Steven |