When my code sorts the inputs, why doesn't it work in certain scenarios?

Question

I am new to Python. First, the code is supposed to take an input (in the form of "x/y/z" where x,y, and z are any positive integer) and split it into three different variables.

input = raw_input()
a, b, c = input.split("/", 2)

I want the second part of my code to take these three variables and sort them based on their numerical value.

order = [a, b, c]
print order
order.sort()
print order

While this works perfectly for most inputs, I have found that for inputs "23/9/2" and "43/8/2" the output has not been sorted so is not returned in the correct order. Any thoughts as to what could be causing inputs such as these to not work?

Answer 1

The issue is that you are sorting strings, and expecting them to be sorted like integers. First convert your list of strings to a list of ints if you would like numerical sorting.

>>> sorted(['23', '9', '2'])
['2', '23', '9']
>>> sorted(map(int, ['23', '9', '2']))
[2, 9, 23]

Here is how you could rewrite your code:

input = raw_input()
a, b, c = map(int, input.split("/", 2))
order = [a, b, c]
print order
order.sort()
print order

If you need to convert them back to strings, just use map(str, order). Note that on Python 2.x map() returns a list and on 3.x it will return a generator.