[Python-Dev] Make _strptime only time.strptime implementation?

Brett C. drifty@alum.berkeley.edu
Fri, 09 May 2003 19:13:35 -0700


Guido van Rossum wrote:
> [Brett]
> 
>>>>I got a single email from someone asking me to change the
>>>>functionality so that it would raise an exception if part of the
>>>>input string was not parsed.
>>>
> [Guido van Rossum]
> 
>>>That sounds like a good idea on the face of it.  Or will this break
>>>existing code?
> 
> 
> [Brett]
> 
>>Maybe.  If they depend on some specific behavior on a platform that offers
>>it, then yes, there could be issues.  But since the docs are so vague if
>>it does break code it will most likely be because someone didn't follow
>>the warnings in the spec.
> 
> 
> If you add some flag to control this behavior, defaulting to strict,
> then at least people who rely on the old (non-strict) behavior can use
> the flag rather than redesign their application.
> 

But the problem is that I have no idea what the old behavior is.  Since 
the spec is so vague and open I have no clue what all the various libc 
versions do.  I have just been patching strptime the best I can to 
handle strange edge cases that pop up and work as people like Kevin need 
it to.

Unless you are suggesting a flag that when set controls whether the 
Python version or a libc version if available is used, which I guess 
could work as a transition to get people to move over.  Is this what you 
are getting at, Guido?  And if it is, do you want it at the function or 
module level?  I say function, but that is because it would be easier to 
code.  =)

>>And while we are on this subject, does anyone have any issues if I cause
>>_strptime to recognize UTC and GMT as timezones?  The Solaris box I always
>>use to do libc strptime comparisons to does not recognize it as an
>>acceptable value for %Z, but since it is a known fact that neither have
>>daylight savings I feel _strptime should recognize this fact and set the
>>daylight savings value to 0 insteading of raising an error saying it
>>doesn't know about that timezone.
>>
>>Any objections to the change?
> 
> 
> Go for it.
> 

Great.  Once we have settled on this possible strict flag I will make 
the change to _strptime.

-Brett