def remove_punctuation(s):
    """Strip all punctuation, except "_", "/" , "-" from s."""

    punctuation = "!\"#$%&'()*+,/.:;<=>?@[\\]^`{|}~"

    s_sans_punct = ""
    for letter in s:
        if letter not in punctuation:
            s_sans_punct += letter
    return s_sans_punct