def extract_mutations(mutation_string, offset=0):
    """
    Turns a string containing mutations of the format I100V into a list of tuples with
    format (100, 'I', 'V') (index, from, to)

    Parameters
    ----------
    mutation_string : str
        Comma-separated list of one or more mutations (e.g. "K50R,I100V")
    offset : int, default: 0
        Offset to be added to the index/position of each mutation

    Returns
    -------
    list of tuples
        List of tuples of the form (index+offset, from, to)
    """
    if mutation_string.lower() not in ["wild", "wt", ""]:
        mutations = mutation_string.split(",")
        return list(map(
            lambda x: (int(x[1:-1]) + offset, x[0], x[-1]),
            mutations
        ))
    else:
        return []