[icalendar-checkins] r19617 - in iCalendar/trunk: doc src/icalendar

[Max M]

dreamcatcher at codespeak.net wrote:

>Author: dreamcatcher
>Date: Mon Nov  7 21:41:55 2005
>New Revision: 19617
>
>- Changed UTC tzinfo to a singleton so the same one is used everywhere
>  
>

Hi Sidney,

I find the above behaviour confusing.

The problem is the difference here: "FixedOffset()", "LocalTimezone()", 
"UTC".

Two timezones are classes and a single one is an object.

You changed UTC from a class to an object to make a singleton out of it. 
Why was that necessary? Do you use it for equality comparison somewhere?

If it is only for a minor speedup, I think that will be offset by 
programmers spending time figuring out the difference.

In that case I would have found it better if you made an instance an 
called it "utc" or something like that.


class UTC(tzinfo):

    """UTC tzinfo subclass"""

    def utcoffset(self, dt):
        return ZERO

    def tzname(self, dt):
        return "UTC"

    def dst(self, dt):
        return ZERO

utc = UTC() # singleton


Is there any major complaints if i change it to that?

It *is* only a 0.11 version, so backwards incompatible changes should be ok.

The fix is also easy for packages using it.

from icalendar import utc as UTC


A backwards compatible fix would be to add a call method to the class:

    def __call__(self):
        "FixedOffset and LocalTimezone are both classes."
        pass

But that feels a bit hackish.

-- 

hilsen/regards Max M, Denmark

http://www.mxm.dk/
IT's Mad Science

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