[Python-Dev] Boolean transition

2002年3月11日 14:28:54 +1300 (NZDT)

Tim Peters <tim.one@comcast.net>:
> There's nothing reprehensible about, e.g.,
>> days_in_year = 365 + is_leap(year)

This is bug-prone, because it relies on is_leap always
returning a "normalised" boolean value. I don't think
it would be a bad thing if you had to write it
 days_in_year = 365 + ord(is_leap(year))
or, even better,
 days_in_year = 365 + bit(is_leap(year))
where bit() is a function that takes a boolean (and only
a boolean) and returns 0 or 1.
> print [("off", "on")[switch] for switch in switch_list]

No, no, what you really mean is
 print [{False:"off", True:"on"}[switch] for switch in switch_list]
or perhaps
 print ["on" if switch else "off" for switch in switch_list]
and similarly
 days_in_year = 365 + 1 if is_leap(year) else 0
(Yes, I know that one's already been rejected. I can't stop
liking it, though...)
Greg Ewing, Computer Science Dept, +--------------------------------------+
University of Canterbury,	 | A citizen of NewZealandCorp, a	 |
Christchurch, New Zealand	 | wholly-owned subsidiary of USA Inc. |
greg@cosc.canterbury.ac.nz	 +--------------------------------------+