Hi Steven, Sorry for inconvenients. I've posted "unsyntax" example just typing from here, just for exaplain my problem
Finally, I don't understand why every set_<key> set value on wrong section/key. I think setattr syntax is correct, but it doesn't works! About java/python concept, yeah! You all right! But I need a conversion class (as Utility) that expose getter/setter of any keys. Thx! Il giorno venerdì 27 luglio 2012 15:46:59 UTC+2, Steven D'Aprano ha scritto: > On Fri, 27 Jul 2012 05:49:45 -0700, Mariano Di Felice wrote: > > > Hi, > > I have a property file (.ini) that has multiple sections and relative > > keys, as default structure. > > Have you looked at Python's standard INI file library? I already use it! > > http://docs.python.org/library/configparser.html > > > > Now, I would like to export from my utility class methods getter and > > setter. I have started as is: > > > > class Utility: > > > > keys = {"STANDUP": ["st_key1", > "st_key2", "st_key3", "st_key4"], > > "DEFAULT": ["def_key1", > "def_key2", "def_key3", > > "def_key4", "def_key5"]} > > This defines a *shared* class attribute. As it is attached to the class, > not an instance, every instance will see the same shared dict. > > > > def __init__(self): > > for section, keyList in keys .items(): > > for key in keyList: > > As given, this is a SyntaxError. Please do not retype your code from > memory, always COPY AND PASTE your actual code. > > In this case, it is easy to fix the syntax error by fixing the > indentation. But what other changes have you made by accident? > > Your code: > > def __init__(self): > for section, keyList in keys .items(): > > looks for a *global variable* called keys, *not* the shared class > attribute Utility.keys. By design, attributes are not in the function > scope. If you want to access an attribute, whether class or instance, you > must always refer to them as attributes. > > > def __init__(self): > for section, keyList in self.keys.items(): # this will work > > > > setattr(self, "get_%s" % key, > self.get_value(section, > > key)) > > setattr(self, "set_%s" % key, lambda > > value:self.set_value(section, key, value) ) > > > What a mess. What is the purpose of this jumble of code? > > My guess is that you are experienced with Java, and you are trying to > adapt Java idioms and patterns to Python. Before you do this, you should > read these two articles by a top Python developer who also knows Java > backwards: > > http://dirtsimple.org/2004/12/python-is-not-java.html > http://dirtsimple.org/2004/12/java-is-not-python-either.html > > > > > if __name__ == "__main__": > > utility = Utility() > > print "key2: %s" % utility.get_def_key2() ## -> value > return 100 > > Again, another SyntaxError. This can be fixed. But the next part cannot. > > Except for two comments, 100 does not exist in your sample code. Python > doesn't magically set values to 100. The code you give cannot possibly > return 100 since nowhere in your code does it set anything to 100. > > If you actually run the code you provide (after fixing the SyntaxErrors), > you get this error: > > py> utility = Utility() > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "<stdin>", line 5, in __init__ > NameError: global name 'keys' is not defined > > > If you fix that and try again, you get this error: > > py> utility = Utility() > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "<stdin>", line 7, in __init__ > TypeError: get_value() takes exactly 2 arguments (3 given) > > > The results you claim you get are not true. > > > Please read this page and then try again: > > http://sscce.org/ > > > > -- > Steven -- http://mail.python.org/mailman/listinfo/python-list
