def largestNumber(text: str) -> int | None:
    """Find the largest number in a string."""
    number = [int(word) for word in text.split() if word.isdigit()]
    return max(number) if number else None


print("Testing largestNumber()...", end="")
assert largestNumber("I saw 3 dogs, 17 cats, and 14 cows!") == 17
assert largestNumber("One person ate two hot dogs!") == None
assert largestNumber("There are no numbers in this text.") == None
assert largestNumber("I have 2 cats, but the shelter has 20") == 20
text = "It is 82 degrees Fahrenheit, which is 28 degree Celsius."
assert largestNumber(text) == 82
text = "Not one of my 10 penguins are taller than 2 feet 11 inches."
assert largestNumber(text) == 11
assert largestNumber("15-112 is also 112 and is my favorite class.") == 112
assert largestNumber("0 classifies as an integer") == 0
assert largestNumber("") == None
print("Passed!")