parameterized functions: a question of style
Blair Hall
b.hall at irl.cri.nz
Mon Aug 12 04:46:16 CEST 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)
More information about the Python-list
mailing list