About the use of **args

[Zunbeltz Izaola]

Hi

I'm starting a new proyect and i'm in doubt about diferent interfaces
for my clases. My clases will have a lot of attributes and i'm want to
know what aproach could be the best

1) Define one SetAttribute/GetAttribute pair of method for each
attribute.
2) Define one SetAttribute/GetAttribute which argument is a key=value
format.

Any advaice?

Thanks in advance

Zunbeltz Izaola

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[Fredrik Lundh]

Jacek Generowicz wrote:

I find the suggestion that a mangled name is somehow "more private"
than one with a single leading underscore, mildly insulting to the
clients of your code. The implcation is that they can neither work out
the (very complicated and cryptic[*]) mangling scheme, not use dir().

no, the implication is that they can use their own __variables without
having to think about what you're calling your private parts.

in contrast, a _variable is not hidden at all.

</F>

[Zunbeltz Izaola]

"Fredrik Lundh" <fr*****@python ware.com> writes:

I want to sum up some ideas in the thread:

1) setters and getters are not mandatory.

2) The usual way in Python is the direct access

[=] ... b.width # is get
b.width = # is set
del b.width # is del

3) If when setting some attribute there is necesary to have side
effects, it can be achive defining __setattr__ and doing the right
thing depend on the attribute. (It is possible to raise an
exception when the attribute is not in a list/dictionary of usable
attributes, to prevent typos and such kind of errors)

4) __getattr__ can be defined to deal with undefined attributes. For
example it can handle in different way the attributes in a list of
permited attributes (see point 3)

5) attributes that are computed in the fly, can be get like normal
attributes using "property" (property is new in 2.3 or 2.2?)

6) attributes and methods that are no part of the user interface are
named with and _ in the front. (This is a convention)

Are those ideas correct? We can continue with the discussion!!

Zunbeltz
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[Jacek Generowicz]

Zunbeltz Izaola <zu******@wm.lc .ehu.es.XXX> writes:

[snip]

3) If when setting some attribute there is necesary to have side
effects, it can be achive defining __setattr__ and doing the right
thing depend on the attribute. (It is possible to raise an
exception when the attribute is not in a list/dictionary of usable
attributes, to prevent typos and such kind of errors)

4) __getattr__ can be defined to deal with undefined attributes. For
example it can handle in different way the attributes in a list of
permited attributes (see point 3)

5) attributes that are computed in the fly, can be get like normal
attributes using "property" (property is new in 2.3 or 2.2?)
[snip]
Are those ideas correct?

Pretty much.

Properties are available in 2.2. They only work on new style classes.

Just about anything that can be done with properties can be done with
__setattr__ &co, but I think that properties are generally preferred,
if available.