using datetime containers

[indika]

John Machin wrote:
> On Nov 8, 6:06�pm, indika <indikabandar... at gmail.com> wrote:
> > Hi,
> > I'm a newbie to python but have some experience in programming.
>
> So work through the Python tutorial, to find out how it all hangs
> together ... this will be much better than trying to translate
> snippets of language X into Python.
>
>
> > I came across this requirement of using datetime.date objects
> > associated with some another object.
> > eg. a dictionary containing datetime.date => string
> >
> > {
> > datetime.date(2001, 12, 3): 'c',
> > datetime.date(2001, 12, 1): 'a',
> > datetime.date(2001, 12, 2): 'b'
> >
> > }
> >
> > However, the sorting of the dict is not user configurable.
>
> So don't use a dict.
>
> > �The
> > desired behavior would be to provide a datetime.date comparison
> > function to do the sorting(eg. STL map). This may seem a trivial
> > question but I couldn't figure out a way.
>
> datetime.date objects (like almost all objects) already have
> comparison methods built-in. What you need is code to use them. For
> applications like "what was the interest rate on date x" or "what are
> the slope and intercept of a piecewise-linearly-continuous tax table
> for a taxable income of x":
>
> Have two parallel lists, keys and values, in keys order. Use a
> function from the bisect module to find (e.g.) the largest i such that
> keys[i] <= x. If such an i exists, your answer is values[i].
>

thanks.

> > Or else, I would have expected the datatime.date object has a
> > writeable data member, so that iterating a calender with
> > itermonthdates would allow me to access that data member.
>
> Sorry, I can't begin to guess what you mean by that.

I was referring to something like this

eg. in an Image processing lib

struct Image
{
char* p_Data; // image data
int i_DataLen; // length of data
void* p_UserData; // user attaches whatever
}
If the lib user attaches some struct related to image name, file
location ... to p_UserData
whenever a Image* is passed around the user has access to those.

Similarly, if a datetime.date object had an attribute which the user
can access he could
d1 = datetime.date.(2008, 1, 1)
d1.UserData = x1 // hypothetical

d2 = datetime.date.(2008, 1, 2)
d2.UserData = x2 // hypothetical

mylist.append([d1, d2])

Hope i'm making some sense :-)