Beginner String formatting question

[Gary Herron]

JAMoore84 at gmail.com wrote:
> Hi all,
>
> I am trying to write a simple program that will accept an integral
> "time" input in the HHMMSS format and output a "HH:MM:SS" form.  My
> code is as follows:
> ========================
> import string
>
> def FormatTime(time):
>   '''Converts an HHMMSS string to HH:MM:SS format.'''
>
>   timeString = str(time)  #converts the num to string
>
>   hours    = [timeString[0], timeString[1]]
>   minutes = [timeString[2], timeString[3]]
>   seconds = [timeString[4], timeString[5]]
>
>   Ftime = "%s:%s:%s",(hours,minutes,seconds)
>   clock = Ftime.join()
>
>   return clock
>   ===========================
>
> when I run it from IDLE, I get this:
>
>   
>>>> Format.FormatTime(time)
>>>>         
> ['1', '1', ':', '2', '2', ':', '3', '3']
> ['1', '1', ':', '2', '2', ':', '3', '3']
>   
The code you posted did not produce the output you are showing.  You'll
have to be more careful with your posting if you expect to get a useful
answer.

Beyond that, there are a bundle of errors in the code that will prevent
it from working:

If you want to carve a string into substrings, use this kind of syntax
  hours = timeString[0:2]
  minutes = timeString[2:4]
  seconds = timeString{4:6]

If you want to combine small strings into longer strings you've got
several choices:
  output = hours + ':' + ...
or
  output = "%s:%s:%s" %  (hours, ...)  #NOTICE the % operator between
the  format string and value tuple

Since both of those produce a  string as output, you have no need of a
join, BUT if you do decide to produce a list of strings that you want to
join into a longer string, you need to use join correctly:
    parts = [hours,minutes,seconds]
    output = ':'.join(parts)

Another error:  If your time starts with an hour that is just a single
digit, then your string will be only 5 digits long (there will be no
leading zero).   In that case, all the extraction of individual fields
based on indexing into the string will be off by one.
> My questions-
> 1) Why is this function printing out twice?
>   
Show us your real code.
> 2)It may be a formatting issue, but I want to have the output as
> "HH:MM:SS", rather than having it broken out into each cell.  I
> thought the 'join' command would do this, but I must not be using it
> properly/understanding something.
>   
See the example above.
> 3)as a side note, I've noticed that the parameter "time" passed in
> must be passed in as a string, otherwise I receive an error that
> "time" is unsubscriptable.  Am I unable to pass in an int and then
> convert it to a string within the function with str()?
>   
Of course you can pass any type into a function.  Then you have to write
the program to operate correctly on whatever the input type is.
> I've been at this for a while, so I may not be able to see the forest
> through the trees at this point.  I'd greatly appreciate any
> suggestions or instruction on these mistakes.
>   
My guess is that's why the code you show does not match the output you
present.
> Best,
>
> Jimmy
>   

Gary Herron