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Re: Beginner Python Help

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Greetings Alan and welcome to Python,

>I just started out python and I was doing a activity where im 
>trying to find the max and min of a list of numbers i inputted.
>
>This is my code..
>
>num=input("Enter list of numbers")
>list1=(num.split())
>
>maxim= (max(list1))
>minim= (min(list1))
>
>print(minim, maxim)
>
>So the problem is that when I enter numbers with an uneven amount 
>of digits (e.g. I enter 400 20 36 85 100) I do not get 400 as the 
>maximum nor 20 as the minimum. What have I done wrong in the code?

I will make a few points, as will probably a few others who read 
your posting.

  * [to answer your question] the builtin function called input [0]
    returns a string, but you are trying to get the min() and max() 
    of numbers; therefore you must convert your strings to numbers

    You can determine if Python thinks the variable is a string or 
    a number in two ways (the interactive prompt is a good place to
    toy with these things).  Let's look at a string:

      >>> s = '200 elephants'
      >>> type(s)                 # what type is s?
      <class 'str'>               # oh! it's a string
      >>> s                       # what's in s?
      '200 elephants'             # value in quotation marks!

   The quotation marks are your clue that this is a string, not a 
   number; in addition to seeing the type.  OK, so what about a 
   number, then?  (Of course, there are different kinds of numbers, 
   complex, real, float...but I'll stick with an integer here.)

      >>> n = 42
      >>> type(n)                 # what type is n?
      <class 'int'>               # ah, it's an int (integer)
      >>> n                       # what's in n?
      42                          # the value

  * Now, perhaps clearer?  max(['400', '20', '36', '85', '100'])
    is sorting your list of strings lexicographically instead of 
    numerically (as numbers); in the same way that the string 
    'rabbit' sorts later than 'elephant', so too does '85' sort 
    later than '400'

  * it is not illegal syntax to use parentheses as you have, but you
    are using too many in your assignment lines; I'd recommend 
    dropping that habit before you start; learn when parentheses are 
    useful (creating tuples, calling functions, clarifying 
    precedence); do not use them here:

       list1 = (num.split())  # -- extraneous and possibly confusing
       list1 = num.split()    # -- just right

  * also, there is also Tutor mailing list [1] devoted to helping 
    with Python language acquisition (discussions on this main list 
    can sometimes be more involved than many beginners wish to read)

I notice that you received several answers already, but I'll finish 
this reply and put your sample program back together for you:

  num = input("Enter list of numbers: ")
  list1 = list(map(int, num.split()))
  print(list1)
  maxim = max(list1)
  minim = min(list1)
  print(minim, maxim)

You may notice that map [2] function in there.  If you don't 
understand it, after reading the function description, I'd give you 
this example for loop that produces the same outcome.

  list1 = list()
  for n in num.split():
      list1.append(int(n))

The map function is quite useful, so it's a good one to learn early.

Good luck,

-Martin

 [0] https://docs.python.org/3/library/functions.html#input
 [1] https://mail.python.org/mailman/listinfo/tutor/
 [2] https://docs.python.org/3/library/functions.html#map

-- 
Martin A. Brown
http://linux-ip.net/

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Thread

Beginner Python Help Alan Gabriel <alanunny@gmail.com> - 2016-03-18 00:04 -0700
  Re: Beginner Python Help Terry Reedy <tjreedy@udel.edu> - 2016-03-18 03:20 -0400
    Re: Beginner Python Help Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-18 09:44 +0200
  Re: Beginner Python Help Chris Warrick <kwpolska@gmail.com> - 2016-03-18 08:23 +0100
  Re: Beginner Python Help Ben Finney <ben+python@benfinney.id.au> - 2016-03-18 18:26 +1100
  Re: Beginner Python Help "Martin A. Brown" <martin@linux-ip.net> - 2016-03-18 00:50 -0700

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