overwriting method in baseclass

[Harald Massa]

Hello!

I am using a library (= code of so else) within Python. Somewhere in this
library there is:

class foo:
def baa(self, parameters):
print "something"
self.baazanan(some other parameters)
class mirbo(foo):
def baazanan(self, lalala):
print "heylo tada"

class fujiko(foo):
def baazanan(self, ltara):
print "sing a song with me"
.....
now I want to change the common baa-method. so that

def baa(self, parameters):
print "soemthing special"
self.baazanan(some other parameters)

Of course, I use a Python- and GPL-Licence compatible library, I can
change the source of foo, and use my changed library.

But someday, it happened before, there will be an update by the publisher
to that library.... and I have to do all again.

So, what is the most elegant solution to administer these changes?

Harald

[Steven Bethard]

Harald Massa wrote:

Hello!

I am using a library (= code of so else) within Python. Somewhere in this
library there is:

class foo:
def baa(self, parameters):
print "something"
self.baazanan(some other parameters)
class mirbo(foo):
def baazanan(self, lalala):
print "heylo tada"

class fujiko(foo):
def baazanan(self, ltara):
print "sing a song with me"
....
now I want to change the common baa-method. so that

def baa(self, parameters):
print "soemthing special"
self.baazanan(some other parameters)

Of course, I use a Python- and GPL-Licence compatible library, I can
change the source of foo, and use my changed library.

But someday, it happened before, there will be an update by the publisher
to that library.... and I have to do all again.

So, what is the most elegant solution to administer these changes?

Given these classes:

py> class foo:
.... def baa(self):
.... print "something"
.... self.baazanan()
....
py> class mirbo(foo):
.... def baazanan(self):
.... print "heylo tada"
....
py> class fujiko(foo):
.... def baazanan(self):
.... print "sing a song with me"
....

You should be able to redefine the method and assign it to the foo class:

py> def new_baa(self):
.... print "soemthing special"
.... self.baazanan()
....
py> foo.baa = new_baa

Then any instances created after this assignment should use the new baa
method you defined:

py> mirbo().baa()
soemthing special
heylo tada
py> fujiko().baa()
soemthing special
sing a song with me

You also might bring up this point to the maintainer of the library --
if they know your intents, they can make this easier for you...

STeVe

[bruno modulix]

Harald Massa wrote:

Hello!

I am using a library (= code of so else) within Python. Somewhere in this
library there is:
(snip)

now I want to change the common baa-method. so that
(snip)
Of course, I use a Python- and GPL-Licence compatible library, I can
change the source of foo, and use my changed library.

But someday, it happened before, there will be an update by the publisher
to that library.... and I have to do all again.

So, what is the most elegant solution to administer these changes?

<ot>
Use a version control system (svn is quite fine...).
</ot>

--
bruno desthuilliers
ruby -e "print 'o****@xiludom.gro'.split('@').collect{|p|
p.split('.').collect{|w| w.reverse}.join('.')}.join('@')"
--

[Harald Massa]

bruno modulix <on***@xiludom.gro> wrote in

So, what is the most elegant solution to administer these changes?

<ot>
Use a version control system (svn is quite fine...).
</ot>

Thanks for that recommendation, I really do use subversion for some time.
But how can I use it to solve this problem? I do changes to the common
baseclass which is OUTSIDE my development. I quite correctly assume that
the developers of the classlib also use Subversion, alas, having no public
access.

So HOW can SVN be of any use for THIS prob?

Harald

[Marc 'BlackJack' Rintsch]

In <Xn**********************************@195.20.224.1 16>, Harald Massa
wrote:

Thanks for that recommendation, I really do use subversion for some time.
But how can I use it to solve this problem? I do changes to the common
baseclass which is OUTSIDE my development. I quite correctly assume that
the developers of the classlib also use Subversion, alas, having no public
access.

So HOW can SVN be of any use for THIS prob?

Take a look at the Subversion documentation (the "book") and search for
`Vendor branches`.

First paragraph of that section:

As is especially the case when developing software, the data that you
maintain under version control is often closely related to, or perhaps
dependent upon, someone else's data. Generally, the needs of your
project will dictate that you stay as up-to-date as possible with the
data provided by that external entity without sacrificing the stability
of your own project. [...]

The section deals specifically with the situation how to manage 3rd party
source code with subversion which you want to update from time to time and
even apply some modifications.

Ciao,
Marc 'BlackJack' Rintsch

[Harald Massa]

marc,

So HOW can SVN be of any use for THIS prob?
Take a look at the Subversion documentation (the "book") and search
for `Vendor branches`.

[...] The section deals specifically with the situation how to manage 3rd
party source code with subversion which you want to update from time
to time and even apply some modifications.

thank you very much for pointing this out! I did not even dare to hope to
find sth. of this kind with a rcs for MY software.

So I did not even start searching.

Thank you,

Harald