[Tutor] Separating recursion, for loops, and while loops

[Jayprasad J. Hegde]

hello "Guess who?", 

I have modified your program to make it work for 
"while", "for" and the recursive case. 

All the three have a similar behaviour, unlike the original version, and print 
out the dice "values" before terminating by printing out the cumulative values
("total").

problem with "while" version: 
	_no_ return value; you are using "print while_dice..." in the main portion of the code
	My version: returns the total 

problem with the "for" version: 
	1. _no_ return value
	2. redundancy for a short code e.g. 
>        elem=random.randint(1,sides)
>        value=elem. 
	I guess, if it helps you understand better you can stick to it.  
	3. total used on the RHS before "declaring". To avoid this problem
you need to say "total = ..." before this statement. 

I have created a recursive version for you, in case you need some reference. 
Its open to all for comments. 


> 
> And one more thing - the first part, loop_dice, outputs things on different 
> lines - is there any way, without using recursion, to add all the numbers 
> together before printing them?
you mean _juxtapositioning_ (or putting things on the same line)  and
not _addition_ don't you? In that case simply put a comma at the end of
the print statement e.g. "print value,"
> 
> And if I am using recursion, same question - can I output add the numbers 
> together and output them? I'm sure I can, I just don't know how, and would 
> appreciate the enlightenment.
check out the code.  :)

You'll find the code below my "signature" section. 

regards
- JJH
ps - why the anonymity? 

-- 
Human beings were created by water to transport it uphill.
(defun JJHdetails ()
  (format t "~&~A~&~A~&~A"
    "Jayprasad J Hegde, Staff Scientist, KBCS, NCST" "Gulmohar Cross
    Road 9, Juhu, Mumbai 400049." "tel: +91-22-26201606x373"))

-------------------
import random

def loop_dice(rolls, sides):
    if rolls<1:
       print "If you don't play, you can't win or lose."
    elif sides<1:
       print "There are either 0 sides, or infinitely many sides. Trippy."
    total = 0
    while rolls > 0:
       value=random.randint(1,sides)
       rolls=rolls - 1
       print value, 
       total = total + value
    print
    return total 

def for_dice(rolls, sides):
   if rolls<1:
       print "If you don't play, you can't win or lose."
   elif sides <1:
       print "There are either 0 sides, or infinitely many sides. Trippy."
   total = 0
   for elem in range (rolls):
       value=random.randint(1,sides)
       total= value + total
       #'local variable total referenced before assignment'
       print value,
   print
   return total


def rec_dice (myrolls, mysides):
   total = 0
   if (myrolls >= 0):
      value = random.randint (1, mysides)
      print value, 
      total = rec_dice (myrolls - 1, mysides) + value
   return total

   
choice=input(" 0 == while, 1 == for, 2 == rec:")

rolls=input("How many rolls would you like to make?")
sides=input("How many sides would you like to make?")

if choice == 0:
   print loop_dice(rolls,sides)
elif choice == 1:
   print for_dice(rolls,sides)
elif choice == 2:
   print
   print rec_dice (rolls, sides)