Python test case does not run at all, returns nothing

I am writing a function that can turn any input into pig latin. It is assumed that the input will be passed into the function so user input is necessary at this time. I am trying to figure out my test cases for this but am only receiving this input:

Process finished with exit code 0

Can anyone explain why that is? I've outlined my code for both the function and test functions below:

Function

def pig_latinify(word):
    """
    takes input from user
    check IF there is a vowel at beginning
        do this
    ELSE
        do this
    print result

    :param :
    :return:
    :raises:

    """
    if word.isalpha() == False:
        return AssertionError
    elif word[0] in ("a", "e", "i", "o", "u"):
        result = word + "yay"
    else:
        while word[0] not in ("a", "e", "i", "o", "u"):
            word = word[1:] + word[0]
            result = word + "ay"
    print(result)

#pig_latinify()

**Test Code**

    import pytest
    import mock
    from exercise1 import pig_latinify

    word_starting_with_vowel = "apple"
    word_starting_with_consonant = "scratch"
    word_containing_alphanumeric = "HE90LLO"

    def test_word_starting_with_vowel():
        for item in word_starting_with_vowel:
             assert pig_latinify("apple") == "appleyay"


    def test_word_starting_with_vowel_2():
        for item in word_starting_with_vowel:
             assert pig_latinify("is") == "isyay"


    def test_word_starting_with_consonant():
        for item in word_starting_with_consonant:
             assert pig_latinify("scratch") == "atchscray"


    def test_word_containing_alphanumeric():
        for item in word_containing_alphanumeric:
            try:
                pig_latinify("HE90LLO")
            except AssertionError:
                assert True