[Tutor] Is there an easily or shorter way?

Ken G. beachkidken at gmail.com
Tue Dec 16 01:55:17 CET 2014

On 12/15/2014 05:59 PM, Dave Angel wrote:
> On 12/15/2014 04:25 PM, Ken G. wrote:
>> I am sure there is a better way to refine the following lines.
>> Letting x equal a number from 1 to 28, go through 28 separate 'if'
>> statements to print a resulting value that equaled the value of x.
>> For example:
>> x = 8
>> if x = 1, print 'one'
>> if x = 2, print 'two'
>> ...
>> ...
>> if x = 8, print 'eight'
>> ...
>> ...
>> if x = 28, print 'twenty eight'
>> Would a single line using list or dictionary be shorter?
> If this is an assignment, and you quoted it correctly, then you're 
> required to go through 28 if statements.  On the other hand, if that 
> paragraph is just a description of the way you solved it, then yes, it 
> can be improved.  Just making all but the first if statement an elif 
> will make it faster, because once it finds a value, it won't continue 
> checking the remaining ones.
> Still faster would be testing first for fourteen, and making a tree 
> out of the if statements, using > and < comparisons instead of only == 
> comparisons.  Worst case would be about 5 tests.  This would not be 
> more compact, just quicker to execute.
> Faster yet, and somewhat more compact would be to make a tuple or list 
> of 29 items (0 through 28), and just index into it.
> Slower, but more compact, would be to write the kind of library that 
> Danny pointed you to, or the code that Ken/Bod alluded to.
> But the real question is what's your goal.   Your original code isn't 
> legal Python, so you're presumably in a learning mode.  If so, you 
> want to keep it simple, not use 3rd party libraries for something you 
> could do yourself.  And when you're given an assignment, you should do 
> it exactly the way they want it, and only after that's correct (and 
> running), do it also in other ways.  Those other ways could be to 
> improve performance, reduce size, make it more readable (or less, to 
> enter it in obfuscation contests), to make it independent of any 
> loaded libraries, to look like some sample in another language, ...
> My second suggestion, untested:
> if x < 14:
>     if x < 7:
>          if x < 3:
>              if x == 1:
>                    print ("one")
>              else:
>                    print ("two")
>          elif x < 5:
>              if x == 3:
>                    print ("three")
>              else:
>                    print ("four")
> ....
Oh, it is not an assignment, Dave. It is an actual program I am using
for my benefit. I had to figure out on a fly, what is the name of a piece
of property that each number represent. I had to reckon something out
within a limited amount of time I had. Giving the response given here
so far, I could go with a list, dictionary or tuple.

Thanks for your input.


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