On 26/04/2013 00:09, Ethan Furman wrote:
We just fixed NoneType() to return None instead of raising an exception.
Another use-case for calling NoneType is working with ORMs:
result = []
for field in row:
type = get_type(field) # returns int, bool, str, NoneType, ...
result.append(type(field))
if field is None, the resulting call is NoneType(None), and since NoneType
doesn't take any parameters we get an exception.
Is it worth filing a bug to have NoneType accept one optional argument, which
defaults to None, and must be None, else
raise an exception?
Or should it be:
class NoneType:
def __new__(cls, *args, **kws):
return None
Which is basically what my 2.x none() helper function does...
On the one hand, NoneType(None) seems a strange thing to do.
On the other hand:
type(value)(value) == value
would return True for the built-in types (will certain exceptions, such
as when value is float("NaN")).
Let's ask the Zen:
Special cases aren't special enough to break the rules.
Although practicality beats purity.
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