Martin De Kauwe wrote:
Hi,
I have a series of parameter values which i need to pass throughout my
code (>100), in C I would use a structure for example. However in
python it is not clear to me if it would be better to use a dictionary
or build a class object? Personally I think accessing the values is
neater (visually) with an object rather than a dictionary, e.g.
x = params['price_of_cats'] * params['price_of_elephants']
vs.
x = params.price_of_cats * params.price_of_elephants
So currently I am building a series of class objects to hold different
parameters and then passing these through my code, e.g.
class EmptyObject:
pass
self.animal_prices = EmptyObject()
self.price_of_cats = 12 or reading a file and populating the object
I would be keen to hear any reasons why this is a bad approach (if it
is, I haven't managed to work this out)? Or perhaps there is a better
one?
thanks
Martin
Using classes is the best choice.
However, if because there would be too much classes to define so that
you are forced to use your EmptyObject trick, adding attributes to the
inntance dynamically, I'd say that dictionnaries are a more common pattern.
Ideally, you would have something like:
class PriceHolder(object):
@classmethod
def fromFile(cls, filename):
# example of abstract method
pass
class Animals(PriceHolder):
def __init__(self):
self.cat = None
self.elephant = None
class Fruits(PriceHolder):
def __init__(self):
self.banana = None
self.apple = None
Then you would have to write 100 PriceHolder subclasses...
JM
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