[Tutor] Need help adding a funcation

[Dave Angel]

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On 12/01/2011 11:49 AM, Michael Hall wrote:
> On Thu, Dec 1, 2011 at 7:51 AM, Dave Angel<d at davea.name>  wrote:
>
>>   On 12/01/2011 10:33 AM, Michael Hall wrote:
>>
>>> Here is the code I have written.
>>>
>>> # Create main function.
>>> def main():
>>>      a = input('Please Enter a Number: ') # Ask user for input.
>>>      number = int(a)
>>>      x = 1
>>>      sum_of = 0
>>>      while number>   x:
>>>          if number % x == 0:
>>>              sum_of = sum_of + x
>>>          x += 1
>>>      if sum_of == number:
>>>         print(number,'is a Perfect Number')
>>>      elif sum_of<   number:
>>>         print(number,'is a Non-perfect Number')
>>>
>>> main()
>>>
>>> Here is the problem I am having. The program works perfect but I need to
>>> add the following:
>>>
>>> # a) write a function, getDivisors(), that returns a list of all
>>> # of the positive divisors of a given number. for example -
>>> # result = getDivisors(24)
>>> # print(result)
>>> # would yield: "[ 1, 2, 3, 4, 6, 8, 12]"
>>> # b) write a program that uses your function to determine which
>>> # numbers between 1 and 10,000 are perfect. (answer: 6, 28, 496
>>> # and 8128 are perfect!)
>>>
>>> I know that mystring needs to be added. I need help
>>> Thank you in advance
>>>
>>> I don't see any 'mystring' in the source or in the assignment;   why
>> would you think you need it?
>>
>> It asks you to write a function called getDivisors().  You have all the
>> pieces in your present code, but it's all inline.  Probably your professor
>> wants you to learn to code in small functions, so your code is more likely
>> to be reusable.
>>
>> So what part of the function description is unclear?  And is it unclear
>> because you don' t understand one of the math terms, or because you don't
>> know how to code it?    She wants a function that takes a single argument
>> (number), and returns a list
>>
>> def getDivisors(number):
>>        do some stuff
>>        return mylist
>>
>> You'll probably want to write another one that adds up the elements of a
>> list (or you could find it in the stdlib).  Then your main should be pretty
>> straightforward.
>>
>>
>>
>> --
>>
>> Dave


A
>>
>> The truth is I am unsure how to code it. Here is my guess:
>
> def main():
>      a = input('Please Enter a Number: ') # Ask user for input.
>      number = int(a)
>      x = 1
>      sum_of = 0
>      while number>  x:
>          if number % x == 0:
>              sum_of = sum_of + x
>          x += 1
>      if sum_of == number:
>         print(number,'is a Perfect Number')
>      elif sum_of<  number:
>         print(number,'is a Non-perfect Number')
> def getDivisors(number):
>             while count != num:
>          if (num % count) != 0:
>              mylist.append(count)
>              count +=1
>          else:
>              count +=1
>      print(mylist)
>
>
> main()
>
>
> YES, I DO NOT UNDERSTAND HOW OR WHERE TO PUT THE CODE.
> THANK YOU FOR YOUR HELP.
>

You want a separate function, so don't try to put it in the middle of 
the present one.  Put the def *after* the print(mylist) line.

All you can take from the older function is ideas.  Since you wrote it, 
you must know how to write the new one.  The task is much simpler, and 
is a subset of the task the first one did.

You're going to need some form of loop.  Figure out what the limits are 
and see if you can figure out some way to do a for loop between those 
limits.  The work of the loop body will be done by the same
       if number % x == 0:

that you had before, but you do something different than what you did 
before.  Your job is to build a list.

Note to others:  Don't confuse the issue with efficiency, nor with some 
library code.  This is a homework assignment, and it has to be done with 
concepts the OP already has been taught.

-- 

DaveA