Ian Kelly <[email protected]>:
> On Fri, May 25, 2018 at 11:00 PM, Chris Angelico <[email protected]> wrote:
>> # Tri-state logic
>> Maybe = object()
>
> The enum has a nice __str__ though.
I use strings for enums:
class X:
HERE = "HERE"
THERE = "THERE"
EVERYWHERE = "EVERYWHERE"
def __init__(self):
self.location = self.HERE
def move_there(self):
assert self.location is not self.EVERYWHERE
self.location = self.THERE
1. Why self.THERE instead of X.THERE?
X.THERE would work. It would even be preferable if the enums were
used in a published API. However, in general I don't like to sprinkle
the name of a class around its implementation.
2. Whe "is not" instead of "!="?
The enums are defined as strings only as a matter of printing
convenience. They are treated as arbitrary sentinel objects whose
only functional property is their identity. Or course, such sentinel
objects must not be used in contexts where ordinary strings would be
possible values.
Marko
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