parameterized functions: a question of style
Blair Hall
b.hall at irl.cri.nz
Sun Aug 11 22:46:16 EDT 2002
I would be interested in comments / suggestions regarding the following
attempt to generate a family of functions.
Suppose (just for arguments sake) I need various functions of the form y
= x**n, where n is a
parameter, ie I want n to be part of the function definition, not an
argument to it!
I am tempted to write
def gen_fn(n):
def _fn(x):
return x**n
return _fn
I could then obtain different functions like
squared = gen_fn(2)
cubed = gen_fn(3)
so
>>> squared(4)
16
>>> cubed(3)
27
The only alternative I can think of to this would be inheritance, ie
class base(object):
def raise(self,x)
return x ** self.n
class two(base):
def __init__(self):
self.n = 2
class three(base):
def __init__(self):
self.n = 3
This solution leaves me with a class, not a function (which is what I
intended to have),
so there would be a further step needed to export the class methods as
functions.
Any suggestions, gotchas?
(I realize that the first way uses nested scopes, but that's ok from
2.2)
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