> This is something I felt comfortable exploring very early on - to the
> extent of having overused it. I would hate to see you back-end that, as
> I think it is kind of fun to play with. "let's change the boring old
> rules of math..." kind of thing.
>
Yes, operator overloading is a big part of my "math through programming"
curriculum. You want your * and + operators to be "modulo N" for example,
the better to appreciate group theory. Or we might use * to mean 'compose'
as in:
>>> def f(x): return 2*x + 1
>>> def g(x): return x**2
>>> class F(object):
def __init__(self, func):
self.func = func
def __mul__(self, other):
return F(lambda x: self.func(other.func(x)))
def __call__(self,x):
return self.func(x)
>>> of = F(f)
>>> og = F(g)
>>> of(2)
5
>>> f(g(2))
9
>>> h = of*og
>>> h(2)
9
>>> j = og*of
>>> j(2)
25
I think where a lot of kids will first encounter underunder is not in
__init__ but in __name__, as in that "__name__ == '__main__'" trick for
getting scripts to run at the command line, even as they also serve as class
& function repositories for snake charmers in a Python shell.
Kirby
PS: since you've been studying subclassing primitive types using __new__,
maybe you could show us a user-defined floating point type that reports two
numbers equal if their absolute value difference is less than e. Anyone?
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