Way for see if dict has a key

[Bruno Desthuilliers]

Georg Brandl wrote:
> Bruno Desthuilliers wrote:
> 
>> looping wrote:
>>
>>> Michele Petrazzo wrote:
>>>
>>>> Bruno Desthuilliers wrote:
>>>>
>>>>>> but what the better
>>>>>
>>>>>
>>>>> Depends on the context.
>>>>>
>>>>
>>>> If know only one context: see if the key are into the dict... What
>>>> other
>>>> context do you know?
>>>>
>>>
>>> Why do you want to do that ?
>>>
>>> if key in dict:
>>>   value = dict[key]
>>> else:
>>>   value = None
>>>
>>> could be write:
>>
>>
>> value = dict.get(key, None)
> 
> 
> value = dict.get(key)

Yes - but :
1/ not everybody knows that dict.get() takes a second optional param.
Note that, while it happens that the default return value of dict.get()
is the same as in the above example, but it may not have been the case.

2/ Since dict.get() implicitely returns None while getattr() defaults to
raising an AttributeError unless you provide a default, I prefer to be
very explicit when using dict.get().


-- 
bruno desthuilliers
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