Re: MethodType/FunctionType and decorators
On Jul 6, 6:19 am, [EMAIL PROTECTED] (Alex Martelli) wrote: Alex Popescu [EMAIL PROTECTED] wrote: ... frameworks (TestNG is not a unit testing framework, but a full flavored testing framework that fits perfectly functional testing, integration testing, and with some of the very advanced features even performance and load testing). Nice! Does it have any integration/interoperability with FIT/Fitnesse, btw? For certain kinds of functional testing (where the specs are to be mostly written by people with no programming skills but strong business, accounting, c, i.e., people _used_ to thinking in terms of tables and spreadsheets) I find that approach very interesting... Alex That's an interesting idea! We never tried that before but I will definitely look into it. Thanks for the suggestion Alex. ./alex -- .w( the_mindstorm )p. -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
On Jul 5, 3:41 am, [EMAIL PROTECTED] (Alex Martelli) wrote: snip Alex already explained everything beautifully. I will just add a link to the definite guide to descriptors: http://users.rcn.com/python/download/Descriptor.htm Michele Simionato (who spent lot of brain cycles studying descriptors *before* that guide was written :-() -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
On Jul 5, 11:17 am, Michele Simionato [EMAIL PROTECTED] wrote: On Jul 5, 3:41 am, [EMAIL PROTECTED] (Alex Martelli) wrote: snip Alex already explained everything beautifully. I will just add a link to the definite guide to descriptors:http://users.rcn.com/python/download/Descriptor.htm Michele Simionato (who spent lot of brain cycles studying descriptors *before* that guide was written :-() Guys, I appreciate a lot your help and explanations. It looks like I have to read/play a bit more as some of the terms/ideas are pretty new to me (coming to Python with a 10 years Java bag, and only with a small dynlang bag - Ruby, Perl). Once again thanks, ./alex -- .w( the_mindstorm )p. -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
Alex Popescu wrote: On Jul 5, 11:17 am, Michele Simionato [EMAIL PROTECTED] wrote: On Jul 5, 3:41 am, [EMAIL PROTECTED] (Alex Martelli) wrote: snip Alex already explained everything beautifully. I will just add a link to the definite guide to descriptors:http://users.rcn.com/python/download/Descriptor.htm Michele Simionato (who spent lot of brain cycles studying descriptors *before* that guide was written :-() Guys, I appreciate a lot your help and explanations. It looks like I have to read/play a bit more as some of the terms/ideas are pretty new to me (coming to Python with a 10 years Java bag, and only with a small dynlang bag - Ruby, Perl). Once again thanks, Please also realise that for someone new to the language you have dived right into the nitty gritty. This isn't necessarily a bad way to learn, but it does mean that there's a lot of background to assimilate as you go along. Good luck with your studies. regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden --- Asciimercial -- Get on the web: Blog, lens and tag the Internet Many services currently offer free registration --- Thank You for Reading - -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
On Jul 5, 3:32 pm, Steve Holden [EMAIL PROTECTED] wrote: Alex Popescu wrote: On Jul 5, 11:17 am, Michele Simionato [EMAIL PROTECTED] wrote: On Jul 5, 3:41 am, [EMAIL PROTECTED] (Alex Martelli) wrote: snip Alex already explained everything beautifully. I will just add a link to the definite guide to descriptors:http://users.rcn.com/python/download/Descriptor.htm Michele Simionato (who spent lot of brain cycles studying descriptors *before* that guide was written :-() Guys, I appreciate a lot your help and explanations. It looks like I have to read/play a bit more as some of the terms/ideas are pretty new to me (coming to Python with a 10 years Java bag, and only with a small dynlang bag - Ruby, Perl). Once again thanks, Please also realise that for someone new to the language you have dived right into the nitty gritty. This isn't necessarily a bad way to learn, but it does mean that there's a lot of background to assimilate as you go along. Good luck with your studies. I am starting to realize this on my own :-). The true story is that while working on Groovy (I am a committer on this dynlang meant to run on the Java VM: http://groovy.codehaus.org) and reading some Python materials, my interest grew exponentially. And now I have decided to see how other succesfull java project I have co-created (TestNG: http://testng.org) would look like in Python (this giving me the opportunity to explore Python in more depth). Thanks for the encouragement. ./alex -- .w( the_mindstorm )p. regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden --- Asciimercial -- Get on the web: Blog, lens and tag the Internet Many services currently offer free registration --- Thank You for Reading - -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
On Jul 5, 11:16 am, Alex Popescu [EMAIL PROTECTED] wrote: Guys, I appreciate a lot your help and explanations. It looks like I have to read/play a bit more as some of the terms/ideas are pretty new to me (coming to Python with a 10 years Java bag, and only with a small dynlang bag - Ruby, Perl). Once again thanks, ./alex -- .w( the_mindstorm )p. BTW, if you are interested in decorators I should mention my own module, which I upgraded just yesterday to version 2.1: http://www.phyast.pitt.edu/~micheles/python/documentation.html HTH, M.S. -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
On Jul 5, 3:17 pm, Alex Popescu [EMAIL PROTECTED] wrote: The true story is that while working on Groovy (I am a committer on this dynlang meant to run on the Java VM:http://groovy.codehaus.org) and reading some Python materials, my interest grew exponentially. And now I have decided to see how other succesfull java project I have co-created (TestNG:http://testng.org) would look like in Python (this giving me the opportunity to explore Python in more depth). If you are interested in testing, you should give a look at 1) doctest; 2) py.test (Python unittest framework should be old hat to you and not worth looking at). Michele Simionato -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
On Jul 5, 5:01 pm, Michele Simionato [EMAIL PROTECTED] wrote: On Jul 5, 3:17 pm, Alex Popescu [EMAIL PROTECTED] wrote: The true story is that while working on Groovy (I am a committer on this dynlang meant to run on the Java VM:http://groovy.codehaus.org) and reading some Python materials, my interest grew exponentially. And now I have decided to see how other succesfull java project I have co-created (TestNG:http://testng.org) would look like in Python (this giving me the opportunity to explore Python in more depth). If you are interested in testing, you should give a look at 1) doctest; 2) py.test (Python unittest framework should be old hat to you and not worth looking at). Michele Simionato Thanks for the pointers Michele. I have heard about those and their are on my todo list. However, the features of TestNG are very advanced and I don't think they are available in other frameworks (TestNG is not a unit testing framework, but a full flavored testing framework that fits perfectly functional testing, integration testing, and with some of the very advanced features even performance and load testing). But I will make sure I am taking a look at the ones you pointed me to (and I think I have a longer list available around). bests, ./alex -- .w( the_mindstorm )p. -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
Alex Popescu [EMAIL PROTECTED] wrote: ... frameworks (TestNG is not a unit testing framework, but a full flavored testing framework that fits perfectly functional testing, integration testing, and with some of the very advanced features even performance and load testing). Nice! Does it have any integration/interoperability with FIT/Fitnesse, btw? For certain kinds of functional testing (where the specs are to be mostly written by people with no programming skills but strong business, accounting, c, i.e., people _used_ to thinking in terms of tables and spreadsheets) I find that approach very interesting... Alex -- http://mail.python.org/mailman/listinfo/python-list
MethodType/FunctionType and decorators
Hi all! I am pretty new to Python, so please excuse me if I am missing something. Lately, I've been playing with decorators and I am a bit confused about some behavior. Here is the code that puzzles me: in python shell: def function(): pass class A(object): def method(self): pass from types import MethodType from types import FunctionType if type(function) is FunctionType: print this is what I expect if type(A.method) is MethodType: print this is what I expect so far so good... everything seems logical. But if a decorator is declared things are becoming different: def deco(function): if type(function) is MethodType: print MethodType elif type(function) is FunctionType: print FunctionType @deco def function2(): pass # == this prints out FunctionType (oke) class A(object): @deco def method(self): pass # == this prints out FunctionType (???) Can somebody shed some light on why I am seeing this? (Using Python 2.5.1 on Win XP). TIA, ./alex -- .w( the_mindstorm )p. -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
On Jul 5, 1:52 am, Alex Popescu [EMAIL PROTECTED] wrote: Hi all! I am pretty new to Python, so please excuse me if I am missing something. Lately, I've been playing with decorators and I am a bit confused about some behavior. Here is the code that puzzles me: in python shell: def function(): pass class A(object): def method(self): pass from types import MethodType from types import FunctionType if type(function) is FunctionType: print this is what I expect if type(A.method) is MethodType: print this is what I expect so far so good... everything seems logical. But if a decorator is declared things are becoming different: def deco(function): if type(function) is MethodType: print MethodType elif type(function) is FunctionType: print FunctionType @deco def function2(): pass # == this prints out FunctionType (oke) class A(object): @deco def method(self): pass # == this prints out FunctionType (???) Can somebody shed some light on why I am seeing this? (Using Python 2.5.1 on Win XP). TIA, ./alex -- .w( the_mindstorm )p. First of all I should correct my example to use isinstance(function_or_method, builtin_factory_function). Secondly, I guess what is happening is the following: - when testing from outside the class definition, the function is already attached to the class instance and this is the reason why its type is instancemethod - for decorators, my test is executed before the class is defined and so at that moment the function is still a function; it will become a methodinstance only after the class definition is closed Is this correct or am I just fabulating here? TIA, ./alex -- .w( the_mindstorm )p. -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
Alex Popescu [EMAIL PROTECTED] wrote: ... - when testing from outside the class definition, the function is already attached to the class instance and this is the reason why its type is instancemethod To be more precise: when you access any attribute of a class (or instance thereof), Python checks if that attribute is a descriptor (i.e. the attribute's type has a __get__ method -- there are finer distinctions based on whether it also has a __set__ method, i.e. is or isn't a data descriptor, but they don't come into play here). A function does have in its type a __get__ method, IOW every (Python-coded) function is a descriptor (a non-data one, btw). So, when you access C.f where C is a class and f's type is Python-coded function, you get the results of calling __get__ on that f object itself. Those results are... the envelope, please!... ta-da: a newly minted method object (whose im_func is f). - for decorators, my test is executed before the class is defined and so at that moment the function is still a function; it will become a methodinstance only after the class definition is closed The function object will never become a method object; it will remain a function object (and you can get at it with C.__dict__['f'] for example); but if you access that name as an attribute of C (or of an instance of C), e.g. as C.f or getattr(C, 'f'), f.__get__ will be called (and return a freshly minted method object whose im_func is f). Is this correct or am I just fabulating here? You have roughly the right idea (as far as decorators are concerned), just a slightly skewed vision of the rapport between function objects and method objects, which I hoped I helped clarify. Here are a few toy-level examples of what I've been saying, I hope they can further help your understanding of function vs method issues: def f(): pass ... class C(object): pass ... a=C.f Traceback (most recent call last): File stdin, line 1, in module AttributeError: type object 'C' has no attribute 'f' C.f = f a=C.f b=C.f a == b True a is b False type(a), type(b) (type 'instancemethod', type 'instancemethod') a.im_func, b.im_func (function f at 0x66030, function f at 0x66030) a.im_func is f is b.im_func True c=f.__get__(C) type(c) type 'instancemethod' c.im_func function f at 0x66030 c.im_func is C.__dict__['f'] is f True Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: MethodType/FunctionType and decorators
Alex Popescu wrote: - for decorators, my test is executed before the class is defined and so at that moment the function is still a function; it will become a methodinstance only after the class definition is closed Closer, but still not quite right. Even after the class is defined, the function sitting inside it is still just an ordinary function. You can see this by looking at A.__dict__['method'] An instancemethod is only created when you look the method up in an instance, i.e. a = A() a.method The instancemethod encapsulates a value for 'self' and a reference to the underlying function. This is known as a bound method. (You also get an instancemethod if you look the method up in the class, i.e. A.method but in that case the instancemethod doesn't contain a value for 'self', and is known as an unbound method.) -- Greg -- http://mail.python.org/mailman/listinfo/python-list
