[Tutor] reverse a number (was no subject)

[Chris Kassopulo]

On Fri, 9 Aug 2002 17:39:48 +0530
"Anand Ramakrishna" <anandrs@hexaware.com> wrote:

> Hi,
>     I am having a strange problem with my python code for reversing a
>     number. I tried it on a few combinations and works fine with most
>     of them except when the number starts in '1'. If I give input as
>     123 it reverses and displays as 442. If I give input as 12 it
>     reverses and displays as 12. Where as if I give any other number,
>     it reverses properly and displays the correct result. The code is
>     pasted below.
>  
>  
>  
> print 'This program accepts a number and then reverses it'
> number = int(raw_input("Enter a number = "))
> temp_var = 0
>  
> while (number/10) > 1 :
>   temp_var = (temp_var*10) + (number%10)
>   number = number/10
> else:
>   temp_var = (temp_var*10) + number
>   print 'The reversed number is ', temp_var 
>  
> 

Greetings,

Ahem, sorry about the last mail.

To do this without using a string I had to loop through
the number twice.  The first time to see how many digits,
the second to actually compute the number.

It's mighty ugly, but it works.  There must be a better
way.
__________________________________________________________

print 'This program accepts a number and then reverses it'

userInput = int(raw_input("Enter a number = "))

# initialize variables  
tempVar = 0
i = 0

# determine number of digits
number = userInput

while number >= 10:
  number = number/10
  i += 1

# compute reversed number
number = userInput

while number >= 10:
  tempVar = tempVar + (number%10)*10**i
  print (number%10)*10**i
  number = number/10
  i -= 1

else:
  print (number%10)*10**i
  number = tempVar + number
  print 'The reversed number is', number
__________________________________________________________ 

Chris Kassopulo _/\_ Linux User #199893 _/\_ Slackware