OOP with MyTime

MRAB python at mrabarnett.plus.com
Thu Jul 3 15:11:49 CEST 2014


On 2014-07-03 13:51, kjakupak at gmail.com wrote:
> On Wednesday, July 2, 2014 4:02:00 PM UTC-4, MRAB wrote:
>> >
>>
>> If you want 'between' to be an instance method of the MyTime class, it
>>
>> needs 'self' as well as the 2 arguments 't1' and 't2'.
>>
>>
>>
>> You can then compare the hours, minutes and seconds of self against
>>
>> those of t1 and t2:
>>
>>
>>
>>      def between(self, t1, t2):
>>
>>          return (t1.hours, t1.minutes, t1.seconds) <= (self.hours,
>>
>> self.minutes, self.seconds) and (self.hours, self.minutes, self.seconds)
>>
>> <= (t2.hours, t2.minutes, t2.seconds)
>>
>>
>>
>> That could be shortened further using chained comparisons.
>>
>>
>>
>> Note that the code assumes that the times t1 and t2 are ordered, i.e.
>>
>> that time t1 is not later/greater than time t2.
>
> So I've now gotten this:
> class MyTime:
>
>      def __init__(self, hrs=0, mins=0, secs=0):
>          self.hours = hrs
>          self.minutes = mins
>          self.seconds = secs
>
>          if self.seconds >= 60:
>              self.minutes += self.seconds // 60
>              self.seconds = self.seconds % 60
>
>          if self.minutes >= 60:
>              self.hours += self.minutes // 60
>              self.minutes = self.minutes % 60
>
>          if self.hours >= 24:
>              self.hours = self.hours % 24
>
>      def get_sec(self):
>          return (self.hours * 60 + self.minutes) * 60 + self.seconds
>
>      def __str__(self):
>          return "{:02d}:{:02d}:{:02d}".\
>                 format(self.hours, self.minutes, self.seconds)
>
>      def between(self, t1, t2):
>          return (t1.hours, t1.minutes, t1.seconds) <= (self.hours, self.minutes, self.seconds) and (self.hours, self.minutes, self.seconds) <= (t2.hours, t2.minutes, t2.seconds)
>
>
> t1 = MyTime(9, 59, 59)
> print("t1 =", t1)
>
> t2 = MyTime(10, 0, 1)
> print("t2 =", t2)
>
> t3 = MyTime(10, 0, 0)
> print("t3 =", t3)
>
> print("between(t2, t3, t1) =", between(t2, t3, t1))
> print("between(t1, t3, t2) =", between(t1, t3, t2))
> print("between(t3, t1, t2) =", between(t3, t1, t2))
> print("between(t1, t2, t3) =", between(t1, t2, t3))
>
> Am I on the right track or? Not sure where to go from here
>
You need to decide whether you want 'between' to be a method of the
MyTime class or a separate function.

In the above code it's defined as a method, so you can say:

     t2.between(t3, t1)

which means "is t2 between t3 and t1?".

That would return False because t3 is greater than t1, but:

     t2.between(t1, t3)

would return True.

(I _did_ say that it assumes that the times are ordered.)

BTW, gmail is messing up your messages. This will tell you how to fix
it:

https://wiki.python.org/moin/GoogleGroupsPython




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