Find highest and lowest number from the string of numbers

Question

I'm trying to write a function that returns the highest and lowest number in a list.

def high_and_low(numbers):

    return max(numbers), min(numbers)

print(high_and_low("1 2 8 4 5"))

But I have this result:

('8', ' ')

Why do I have ' ' as a lowest number?

Answer 1

You are passing string to a function. In order to achieve the desired result, you need to split the string and then type-cast each element to int . Then only your min and max function will work expectedly. For example:

def high_and_low(numbers):
    #    split numbers based on space     v
    numbers = [int(x) for x in numbers.split()]
    #           ^ type-cast each element to `int`
    return max(numbers), min(numbers)

Sample Run:

>>> high_and_low("1 2 8 4 5")
(8, 1)

Currently your code is finding the minimum and maximum value based on lexicographical order of the characters.

Answer 2

In order to achieve your desired result you can call split() on the string you are passing in. This essentially creates a list() of your input string—which you can call the min() and max() functions on.

def high_and_low(numbers: str):
    """
    Given a string of characters, ignore and split on
    the space ' ' character and return the min(), max()

    :param numbers: input str of characters
    :return: the minimum and maximum *character* values as a tuple
    """
    return max(numbers.split(' ')), min(numbers.split(' '))

As others have pointed out you can also pass in a list of values you'd like to compare and can call the min and max functions on that directly.

def high_and_low_of_list(numbers: list):
    """
    Given a list of values, return the max() and 
    min()

    :param numbers: a list of values to be compared
    :return: the min() and max() *integer* values within the list as a tuple
    """
    return min(numbers), max(numbers)

Your original functions does technically work, however, it is comparing numerical values for each character and not just the integer values.

Answer 3

Another (faster) way using mapping:

def high_and_low(numbers: str):
    #split function below will use space (' ') as separator
    numbers = list(map(int,numbers.split()))
    return max(numbers),min(numbers)

Answer 4

You can split your string by ' ' and pass it as Array

def high_and_low(numbers):
    # split string by space character
    numbers = numbers.split(" ")
    # convert string array to int, also making list from them
    numbers = list(map(int, numbers))
    return max(numbers), min(numbers)

print(high_and_low("1 2 10 4 5"))

Answer 5

use numbers_list=[int(x) for x in numbers.split()] and use numbers_list in min() and max() . split() turns '1 23 4 5' into ['1','23','4','5'] ; and by using a list comprehension all the strings get converted to integers.