Python is wierd!

[Richard Jones]

[Jonathan]
> 1. There are no keywords to declare static or instance variables; it
> all depends where they are placed(whether it's right after the <class>
> statement, or inside a <def>). Isn't it harder for other programmers to
> know at one glance what type of attributes the class define?

   I thought it was perfectly clear - much clearer than some other languages :)

   Static attributes are assigned at class definition. Instance attributes are 
assigned to an instance once it's created. That's pretty straightforward. If 
there's a confusion at a later stage about whether an attribute is instance- or 
class- then you've probably got a fundamental design problem in your class...


> 2. No *formal* declaration of static class methods, e.g. no 'static'
> keyword (though i'm not sure how useful static methods are in OOP
> design). I read somewhere in this newsgroup that the workaround way is
> to define the method outside of the class - doesn't it break
> the 'encapsulation' a class suppose to have?

   The generally accepted method is to put these utility functions where they 
logically belong: in the module that defines the class, but not in the class 
itself. If it doesn't operate on an instance, what business does it have in the 
class definition. I use static methods in Java for one thing only: utility 
functions. That's because Java won't let me have stand-alone functions. (That's 
not a dig at Java!)


> 3. No keywords to differentiate between passing arguments by reference
> or value! An integer is passed by value(reference to a new copy), while
> a mutable object is by reference. To pass a list by 'value', i know you
> just need to insert one more line(list = [:]), but it seems
> so 'inconsistent' compared to Java or even PHP.

   Nope, everything is pass-by-reference in Python. Even your integer is 
pass-by-reference, but since it's an immutable object, it might _seem_ like 
you're passing the value of the object.


> (Not to mention the number of 'gotchas' listed in the book that are
> bound to trap beginners - *shudder*)

   Gotchas? I've not read the book - are these actually stated in the book as 
gotchas? I'll personally beat on the head of the author if they are :)


      Richard