Am 29.10.2012 16:20 schrieb andrea crotti:
Now on one hand I would love to use only immutable data in my code, but
on the other hand I wonder if it makes so much sense in Python.
You can have both. Many mutable types distinguish between them with
their operators.
To pick up your example,
class NumWrapper(object):
def __init__(self, number):
self.number = number
def __iadd__(self, x):
self.number += x
return self
def __add__(self, x):
return NumWrapper(self.number + x)
So with
number += 1
you keep the same object and modify it, while with
number = number + 1
or
new_number = number + 1
you create a new object.
But more importantly normally classes are way more complicated than my
stupid example, so recreating a new object with the modified state might
be quite complex.
Any comments about this? What do you prefer and why?
That's why I generally prefer mutable objects, but it can depend.
Thomas
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