[Tutor] What is __weakref__ ?
Karim
karim.liateni at free.fr
Tue Jan 18 15:34:12 CET 2011
Hello Bob,
Thanks for this better and simple approach!
To be perfect I would like to be able to do.
>>> type = CategoryType()
>>> type.TRANSISTOR
0
I will use your enums declaration and the range part to use as keys for
enums.
And I will raise a KeyError in toString() to handle invalid litteral.
Thanks!
Regards
Karim
On 01/18/2011 02:24 PM, bob gailer wrote:
> On 1/18/2011 8:08 AM, Karim wrote:
>>
>> I know this is ugly but until now it is the only way (with this side
>> effect) I found to declare Enums class that I _understand_:
>>
>> *class CategoryType(object):
>> """Implements the enumeration and prevent associated newly created
>> instances to redefine enums value via special class variable
>> '__slots__'
>> definition. It makes also, instances have no attributes at all.
>> """
>> __slots__ = ()
>>
>> TRANSISTOR, MOS, BIPOLAR, CAPACITOR, RESISTOR, DIODE, ESD, PAD, \
>> COMPARATOR, OPAMP, ADC, DAC, PLL, OTHER = range(14)
>>
>> def toString ( self, litteral ):
>> """Convert the litteral integer number to its associated
>> string representation."""
>> if litteral == self.TRANSISTOR:
>> return 'transistor'
>> elif litteral == self.MOS:
>> return 'mos'
>> elif litteral == self.BIPOLAR:*
>> [...]
> IMHO this just cries out for a dictionary:
>
> class CategoryType(object):
> __slots__ = ()
> enums = {
> 0: 'transistor',
> 1: 'mos',
> ...
> }
> def toString(self, literal):
> """Convert the literal integer number to its associated string
> representation."""
> return self.enums[literal]
>
> Note this does not handle invalid literal.
>
> If you are happy with range 14) you could alternatively use a list:
> enums = ['transistor, 'mos', ...]
>
> --
> Bob Gailer
> 919-636-4239
> Chapel Hill NC
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