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What is wrong in this example code?

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  What is wrong in this example code? fl <rxjwg98@gmail.com> - 2015-11-12 05:57 -0800
    Re: What is wrong in this example code? fl <rxjwg98@gmail.com> - 2015-11-12 06:07 -0800
      Re: What is wrong in this example code? John Wong <gokoproject@gmail.com> - 2015-11-12 10:10 -0500
      Re: What is wrong in this example code? Larry Hudson <orgnut@yahoo.com> - 2015-11-12 15:59 -0800
        Re: What is wrong in this example code? Nathan Hilterbrand <nhilterbrand@gmail.com> - 2015-11-12 19:24 -0500

#98693 — What is wrong in this example code?

Hi,

I run a code snippet from link:
http://www.python-course.eu/inheritance_example.php

It is found that there is an error in this loop:

for i in xrange(10000):
    x.tick()
print(x)
SyntaxError: invalid syntax


I have modified it to:
for i in x range(10000):
    x.tick()
print(x)
SyntaxError: invalid syntax

it still has an error. What could be wrong?

Thanks,


....
class Clock(object):

    def __init__(self,hours=0, minutes=0, seconds=0):
        self.__hours = hours
        self.__minutes = minutes
        self.__seconds = seconds

    def set(self,hours, minutes, seconds=0):
        self.__hours = hours
        self.__minutes = minutes
        self.__seconds = seconds

    def tick(self):
        """ Time will be advanced by one second """
        if self.__seconds == 59:
            self.__seconds = 0
            if (self.__minutes == 59):
                self.__minutes = 0
                self.__hours = 0 if self.__hours==23  else self.__hours+1
	    else:
		self.__minutes += 1;
	else:
            self.__seconds += 1;

    def display(self):
        print("%d:%d:%d" % (self.__hours, self.__minutes, self.__seconds))

    def __str__(self):
        return "%2d:%2d:%2d" % (self.__hours, self.__minutes, self.__seconds)

x = Clock()
print(x)
for i in xrange(10000):
    x.tick()
print(x)

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#98695

On Thursday, November 12, 2015 at 8:58:33 AM UTC-5, fl wrote:
> Hi,
> 
> I run a code snippet from link:
> http://www.python-course.eu/inheritance_example.php
> 
> It is found that there is an error in this loop:
> 
> for i in xrange(10000):
>     x.tick()
> print(x)
> SyntaxError: invalid syntax
> 
> 
> I have modified it to:
> for i in x range(10000):
>     x.tick()
> print(x)
> SyntaxError: invalid syntax
> 
> it still has an error. What could be wrong?
> 
> Thanks,
> 
> 
> ....
> class Clock(object):
> 
>     def __init__(self,hours=0, minutes=0, seconds=0):
>         self.__hours = hours
>         self.__minutes = minutes
>         self.__seconds = seconds
> 
>     def set(self,hours, minutes, seconds=0):
>         self.__hours = hours
>         self.__minutes = minutes
>         self.__seconds = seconds
> 
>     def tick(self):
>         """ Time will be advanced by one second """
>         if self.__seconds == 59:
>             self.__seconds = 0
>             if (self.__minutes == 59):
>                 self.__minutes = 0
>                 self.__hours = 0 if self.__hours==23  else self.__hours+1
> 	    else:
> 		self.__minutes += 1;
> 	else:
>             self.__seconds += 1;
> 
>     def display(self):
>         print("%d:%d:%d" % (self.__hours, self.__minutes, self.__seconds))
> 
>     def __str__(self):
>         return "%2d:%2d:%2d" % (self.__hours, self.__minutes, self.__seconds)
> 
> x = Clock()
> print(x)
> for i in xrange(10000):
>     x.tick()
> print(x)

Solved it by this:
print(x)
for i in range(1, 10000):
         x.tick()
print(x)

Thanks,

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#98700

If you are using Python 3 you will need to change xrange to range, but the
error shouldn't be invalid syntax. I remember it should just name name not
found/not defined. So if you are not using Python 3, range and xrange do
still in Python 2 and they have different use case.

So i am really curious how you fixed it. It sounds more like some issue
with space rather, but still glad you solved it somehow.

On Thu, Nov 12, 2015 at 9:07 AM, fl <rxjwg98@gmail.com> wrote:

> On Thursday, November 12, 2015 at 8:58:33 AM UTC-5, fl wrote:
> > Hi,
> >
> > I run a code snippet from link:
> > http://www.python-course.eu/inheritance_example.php
> >
> > It is found that there is an error in this loop:
> >
> > for i in xrange(10000):
> >     x.tick()
> > print(x)
> > SyntaxError: invalid syntax
> >
> >
> > I have modified it to:
> > for i in x range(10000):
> >     x.tick()
> > print(x)
> > SyntaxError: invalid syntax
> >
> > it still has an error. What could be wrong?
> >
> > Thanks,
> >
> >
> > ....
> > class Clock(object):
> >
> >     def __init__(self,hours=0, minutes=0, seconds=0):
> >         self.__hours = hours
> >         self.__minutes = minutes
> >         self.__seconds = seconds
> >
> >     def set(self,hours, minutes, seconds=0):
> >         self.__hours = hours
> >         self.__minutes = minutes
> >         self.__seconds = seconds
> >
> >     def tick(self):
> >         """ Time will be advanced by one second """
> >         if self.__seconds == 59:
> >             self.__seconds = 0
> >             if (self.__minutes == 59):
> >                 self.__minutes = 0
> >                 self.__hours = 0 if self.__hours==23  else self.__hours+1
> >           else:
> >               self.__minutes += 1;
> >       else:
> >             self.__seconds += 1;
> >
> >     def display(self):
> >         print("%d:%d:%d" % (self.__hours, self.__minutes,
> self.__seconds))
> >
> >     def __str__(self):
> >         return "%2d:%2d:%2d" % (self.__hours, self.__minutes,
> self.__seconds)
> >
> > x = Clock()
> > print(x)
> > for i in xrange(10000):
> >     x.tick()
> > print(x)
>
> Solved it by this:
> print(x)
> for i in range(1, 10000):
>          x.tick()
> print(x)
>
> Thanks,
> --
> https://mail.python.org/mailman/listinfo/python-list
>

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#98722

On 11/12/2015 06:07 AM, fl wrote:
> On Thursday, November 12, 2015 at 8:58:33 AM UTC-5, fl wrote:
>> Hi,
>>
<snip>
>>      def tick(self):
>>          """ Time will be advanced by one second """
>>          if self.__seconds == 59:
>>              self.__seconds = 0
>>              if (self.__minutes == 59):
>>                  self.__minutes = 0
>>                  self.__hours = 0 if self.__hours==23  else self.__hours+1
>> 	    else:
>> 		self.__minutes += 1;
>> 	else:
>>              self.__seconds += 1;
<snip>

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 -=-

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#98739

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.

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