def cat2num(x):
    """ 
    Return the int value of a given category

    Parameters
    ----------
    x : string
        value can either be: 'bike' 'car' 'motorcycle' 'other' 'truck' 'van'

    Returns
    -------
    int
        value from 0 to 5 included corresponding to the int equivalent of the category input
    """
    if x == "bike":
        return 0
    if x == "car":
        return 1
    if x == "motorcycle":
        return 2
    if x == "other":
        return 3
    if x == "truck":
        return 4
    if x == "van":
        return 5