def hammingDistance(str1, str2):
    """ Returns the number of `i`th characters in `str1` that don't match the `i`th character in `str2`.
    Args
    ---
    `str1 : string` The first string

    `str2 : string` The second string

    Returns
    ---
    `differences : int` The differences between `str1` and `str2`
    """
    # Convert strings to arrays
    a = list(str1)
    b = list(str2)
    # Determine what n equals
    if len(a) < len(b):
        n = len(a)
    else:
        n = len(b)
    # Increment the number of distances for each difference
    differences = 0
    for i in range(n):
        if a[i] != b[i]:
            differences += 1
    return differences