setting property to type other than what is given

[Lee Harr]

On 2004-05-08, Lee Harr <missive at frontiernet.net> wrote:
>
> I am just starting to use properties, and wonder what you
> might think of this ...
>
>
> class RNumber(object):
>     def __init__(self, n, nmin, nmax):
>         self.nmin = nmin
>         self.nmax = nmax
>         self.n = n
>
>     def _get_n(self):
>         return self._n
>
>     def _set_n(self, n):
>         if n == 'max':
>             self._n = self.nmax
>         elif n == 'min':
>             self._n = self.nmin
>         else:
>             self._n = min(self.nmax, n)
>             self._n = max(self.nmin, self._n)
>
>     n = property(_get_n, _set_n)
>
>
>>>> a = RNumber(5, 0, 10)
>>>> a.n
> 5
>>>> a.n = -3
>>>> a.n
> 0
>>>> a.n = 'max'
>>>> a.n
> 10
>>>> a.nmax = 50
>>>> a.n = 'max'
>>>> a.n
> 50
>



Could even go like this ...


class RNumber(object):
    def __init__(self, n, nmin, nmax):
        self.nmin = nmin
        self.nmax = nmax
        self.n = n

    def _get_n(self):
        n = self._n
        if n == 'max':
            n = self.nmax
        elif n == 'min':
            n = self.nmin
        return n

    def _set_n(self, n):
        if n == 'max':
            self._n = n
        elif n == 'min':
            self._n = n
        else:
            self._n = min(self.nmax, n)
            self._n = max(self.nmin, self._n)

    n = property(_get_n, _set_n)


>>> a = RNumber(5, 0, 10)
>>> a.n = 'max'
>>> a.n
10
>>> a.nmax = 12
>>> a.n
12