[Tutor] quick OO pointer

[shawn bright]

Way cool, thanks a lot. I have one more small question.
If my script that needs to call a function from another module, and the
module itself both require, say, the string module.... do i need to import
it in both?
If i just import string on my original script, will the module know what to
do with it?
and if so, is that good practice ?

thanks again
shawn


On 8/7/06, Alan Gauld <alan.gauld at freenet.co.uk> wrote:
>
> > now, i have a few functions in some scripts that i would like to
> > reuse
> > across the board. But, they dont really fit the "object" thing, i
> > dont
> > thing. Basically, i have a bunch of functions that do different
> > things and i
> > would like one script to hold them all.
>
> You can put normal functions in a module and reuse them sure.
> If they operate on the same kinds of data then a class would be
> more appropriate but otherwise functions are fine.
>
> Its probably good to try to group them into families if possible.
> And you definitely want to use Functional Programming principles
> to maximise reuse. By that I mean:
> 1) No use of global variables
> 2) Pass everything in by parameters
> 3) Use default values to minimise the number of values the user sets
> 4) pass multiple values back in tuples where appropriate
> 5) make sure that the same set of input values always
>     returns the same value - no hidden state
>
> Consider a number of smaller modules with related functionns too.
> Its tempting to just create a module called mystuff or similar that
> holds everything, but you then wind up with every project
> depending on mystuiff and small changes affect lots of code.
> Better to have small modules with only a few functions that can
> be imported as needed. Grouping the functions around the kind
> of data they manipulate is a good start - but that brings us back
> to objects again :-)
>
>
> > def write_something_to_log(logfile, something)
> >    f = open(logfile, 'a')
> >    f.write('%s\n' % something)
> >    f.close()
> >    return 'success'
> >
> > and i wanted to use this same function in about four different
> > scripts, do i
> > need a class ? Do i need to just create a script full of common
> > functions
> > that i can access ? and if so, how ?
>
> ##############
> # file: mylogger.py
> def write_something_to_log(logfile, something)
>     f = open(logfile, 'a')
>     f.write('%s\n' % something)
>     f.close()
>     return 'success'
> ######################
>
> #############
> # file myprog.py
> import mylogger
>
> mylogger.write_something('logfile.txt', 'hello world')
> ##############
>
> As simple as that!
> Just make sure the module file is where it can be found by import...
>
> More on creating modules in my tutorial topic on "Functions &
> Modules".
>
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld
>
>
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