what is the idiom for copy lots of params into self?

Steve Holden steve at holdenweb.com
Thu Jan 11 01:03:26 CET 2007


Jean-Paul Calderone wrote:
> On 10 Jan 2007 14:46:54 -0800, Emin <emin.shopper at gmail.com> wrote:
>> Dear Experts,
>>
>> When writing large classes, I sometimes find myself needing to copy a
>> lot of parameters from the argument of __init__ into self. Instead of
>> having twenty lines that all basically say something like self.x = x, I
>> often use __dict__ via something like:
>>
>> class example:
>>     def __init__(self,a,b,c,d,e,f,g,h,i,j,k,l,m,n):
>>         for name in
>> ['a','b','c','d','e','f','g','h','i','j','k','l','m','n']:
>>             self.__dict__[name] = locals()[name]
>>
>> This saves a lot of code and makes it easier to see what is going on,
>> but it seems like there should be a better idiom for this task. Any
>> suggestions?
> 
> I use a helper, like 
> 
>   http://divmod.org/trac/browser/trunk/Epsilon/epsilon/structlike.py#L35
> 
If you don't want to go that far then this might give you an idea or two:

  >>> class example:
  ...      def __init__(self,a,b,c,d,e,f,g,h,i,j,k,l,m,n):
  ...         for name in inspect.getargspec(example.__init__)[0]:
  ...             print name
  ...
  >>> x = example(1,2,3,4,5,6,7,8,9,10,11,12,13,14)
self
a
b
c
d
e
f
g
h
i
j
k
l
m
n
  >>>

regards
  Steve
-- 
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