[Python-ideas] [Python-Dev] What's the status of PEP 505: None-aware operators?

[Stephan Houben]

Op 29 nov. 2017 22:35 schreef "Greg Ewing" <greg.ewing at canterbury.ac.nz>:


It would read better with some kind of pronoun in there:

   A if it is not None else C

Hypercard's Hypertalk had a special variable "it" that
worked sort of like that.


I  considered that,  but there are two issues.

1. Backward-incompatible change

2. The semantics of
A if B else C
now depends on if B contains 'it',
in which case A gets evaluated unconditionally and prior to B.
What if evaluation of 'it' is itself conditional, e.g.

print("hello") if a or it else print("goodbye")

Note that in the

A if <binary_relation> B else C

proposal the evaluation of the implicit 'it' is never conditional in that
way.

Stephan



-- 
Greg

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