(Very Newbie) Problems defining a variable

Tim Rowe digitig at gmail.com
Fri Dec 12 20:49:40 CET 2008


2008/12/12 John Machin <sjmachin at lexicon.net>:

> (2) sequential search can be very fast if the sequence is in
> descending order of probability of occurence ... you might like to
> consider reversing the order

I find it hard to imagine a bank with so many interest rate thresholds
that the search of the table is likely to be a significant
contribution to the run time!

> (3) for a much longer table, binary search using a function from the
> bisect module could be considered
> (4) in practice, the "default" action would not be "return 0.0";
> perhaps something along these lines:
>
> if balance < -overdraft_limit:
>   raise Exception(...)

That's more likely to be in the withdrawal routine (and is probably
best not handled as an exception, because it's pretty much normal
flow). If a bank provided a service such as the one implemented by
this program, there'd be no need for it to know about overdraft limits
because it's not making actual transactions. Why would they increase
coupling unneccesarily?

-- 
Tim Rowe



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