Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: Nathan Hilterbrand <nhilterbrand@gmail.com>
Newsgroups: comp.lang.python
Subject: Re: What is wrong in this example code?
Date: Thu, 12 Nov 2015 19:24:23 -0500
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Message-ID: <mailman.287.1447419693.16136.python-list@python.org>
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On Thu, Nov 12, 2015 at 6:59 PM, Larry Hudson via Python-list <
python-list@python.org> wrote:

Nothing to do with your original question, just a trivial suggestion which
> you are free to ignore.  You can shorten this tick() method by using the
> divmod() function.  It does a division and returns both the quotient AND
> the remainder.  IOW, given divmod(x, y) it returns the tuple (x/y, x%y).
> It is a very useful function.  Try this:
>
> def tick(self):
>     xtra, self._seconds = divmod(self._seconds + 1, 60)
>     xtra, self._minutes = divmod(self._minutes + xtra, 60)
>     self._hours += xtra
>
> Explanation:  (to shorten this, I'm leaving off the leading "self._" from
> the actual code.)
> The first divmod() sets xtra = (seconds+1) / 60, which is the 'overflow'
> if any, from the division by 60, and seconds is the updated seconds limited
> to 0-59 (the result of (seconds+1) % 60).  The second divmod() does the
> same thing to update minutes (if xtra != 0) and xtra is set to the
> 'overflow' from that division, which is then added to hours.
>
> More confusing perhaps, but definitely shorter.
> As I said above, use it if you want or ignore it if it's too confusing.
>
>      -=- Larry -=-
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

Beat me to the punch.  I was about to suggest something similar, but I
thought that since one using this class would probably be "tick()-ing" more
than "str()-ing", It might also be better to store the value in seconds,
and convert to HH:MM:SS upon stringification; again using divmod:

class Clock(object):

    def __init__(self,hours=0,minutes=0,seconds=0):
        self.set(hours,minutes,seconds)

    def tick(self):
        self.__secs+=1

    def set(self,hours, minutes, seconds):
        self.__secs = seconds + (minutes*60) + (hours*60*60)

    def __str__(self):
        rest, seconds = divmod(self.__secs, 60)
        hours, minutes = divmod(rest, 60)

        return "%02d:%02d:%02d" % (hours, minutes, seconds)

    def display(self):
        print(str(self))


if __name__ == "__main__":

    x = Clock()
    print("Default construction, no parameters, Before ticks: {}".format(x))
    for i in range(10000):
        x.tick()
    print("After ticks: {}".format(x))

    x = Clock(hours=2, minutes=20, seconds=5)
    print("\nConstructor with hours=2, minutes=20, seconds=5: {}".format(x))

    print("Test of display() method: ",end=' ')
    x.display()


This is my first post here, and I am a Python n00b (coming from that
four-letter word language "p***"), so if I broke some top/bottom posting or
formatting rules, I apologize, and would appreciate any posting pointers

Nathan H.