Hi Andreas,
On Aug 3, 2010, at 1:52 AM, Andreas Pfrengle wrote:
I'm trying to define a subclass of int called int1. An int1-object
shall behave exactly like an int-object, with the only difference that
the displayed value shall be value + 1 (it will be used to display
array indices starting at 1 instead of 0). Right now I have:
class int1(int):
def __str__(self):
return int.__str__(self + 1)
However, if I calculate with int1 and int- (or other number) objects,
the result is always coerced to an int (or other number object), e.g:
a = int1(5)
b = 5
print a # "6"
print a+b #"10"
How can I tell int1 to be the "default integer object"? Do I need to
overload *every* mathematical operation method of int, or is there an
easier way?
Maybe you could use:
1) a dict with keys 1..n
2) a simple list (or iterable) subclass with 1-based indices.
class list1(list):
def __new__(cls, *args, **kwargs):
return list.__new__(cls, *args, **kwargs)
def __getitem__(self, key):
return list.__getitem__(self, key-1)
... etcetera
Cheers, Roald
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