A6 - Python Functions

Reference for this assignment

The section on f-strings on page 7 may also be useful.

Additional Information

A function is a subprogram that receives one or more pieces of information as input via it's arguments, and returns one value as output. Once a function is defined, we can call it as often as needed. A function doesn't do anything until it's called.

Examples

def remove_vowels(input_string):
    # Input: any string
    # Output: the input string with vowels removed

    output_string = ""
    for char in input_string:
        if not char.lower() in ['a', 'e', 'i', 'o', 'u']:
            output_string += char

    return output_string


def is_all_even(nums):
    # Input: a list of numbers
    # Output: True if all numbers in the list are even, otherwise False

    for num in nums:
        if num % 2 == 1:
            return False

    # If we've reached here without returning False, it means
    # all numbers are even
    return True


# Test our `remove_vowels` function with two examples
print(remove_vowels("banana"))
print(remove_vowels("Eastview Secondary School!"))


# Test our `is_all_even` function with two examples:
#   one returning True, one returning False
print(is_all_even([2, 8, 10, 14]))
print(is_all_even([1, 2, 4, 12]))


# A function that returns a Boolean value can be used in an `if` statement like this:
if is_all_even([1, 2, 3]):
    print("Yup, all even numbers.")
else:
    print("Nope, at least one odd number in that list.")

This code produces the following output:

bnn
stvw Scndry Schl!
True
False
Nope, at least one odd number in that list.

Learning Goals

Create and call functions that accept one or more arguments and return a value

Suggested Task

Create two functions such that:

Each one accepts at least one argument and returns a value
Use different data types for arguments and returns values, such as strings, lists, numbers, booleans

Call each function twice.

Some function ideas - use one of these ideas if you'd like, then try to come up with at least one of your own ideas:

Input is a list of numbers and a single number; output is how many times the single number appears in the list
Input is a string; output is True if there are at least ten words (the split string method might be useful here)
Input is a string; output is the length of the longest word
Input is a list; output is a list with all numbers of the input list squared
Input is two lists; output is a list containing only the values that are in both input lists (this one would be a little tricky!)