Question

I am performing some simulations in python that generates 1000 results. Each result has multiple properties such as risk, cost etc

I now want to identify results that meeting certain criteria, for example:

Factor 1, cost should be between 10 and 20
Factor 2, risk should be between 0 and 5
Factor 3...
Factor 4...
....

Currently I am using a series of nested if statements to do this. As more factors are added the nesting gets messy. Is there an elegant alternative for filtering given certain criteria?

Answer 1

There are a lot of solutions that depend on your data and preferred code style. E.g.:

>>> conditions = (lambda x: 10 < x.cost < 20, lambda x: 0 < x.risk < 10)
>>> filter(lambda x: all(cond(x) for cond in conditions), result)

Or just:

>>> conditions = lambda x: 10 < x.cost < 20 and 0 < x.risk < 10
>>> filter(conditions, result)

Or:

>>> [r for r in result if 10 < r.cost < 20 and 0 < r.risk < 10]