import re


def title_except(s, exceptions):
    """
    Transforms string so that it will capitalize the first letter in each word, with some exceptions
    Source: https://stackoverflow.com/questions/3728655/titlecasing-a-string-with-exceptions/3729060
    Param: s (str) like "Hi, my name is john smith" and exceptions (list of str) like ["a", "an", "is"]
    Example: title_except("Hi, my name is john smith", ["a", "an", "is"])
    Returns: "Hi, My Name is John Smith"
    """
    word_list = re.split(' ', s)       # re.split behaves as expected
    final = [word_list[0].capitalize()]
    for word in word_list[1:]:
        final.append(word if word in exceptions else word.capitalize())
    return " ".join(final)