def get_new_char(label, shared_obj):
    """
    Get a new single character describing the activity, for the regex

    Parameters
    ------------
    label
        Label of the transition
    shared_obj
        Shared object
    """
    list_to_avoid = ['[', ']', '(', ')', '*', '+', '^', '?', '\r', '\n',
        ' ', '\t', '$', '"', '!', '#', '&', '%', '|', '.', ',', ';', '-',
        "'", '\\', '/', '{', '}', '$']
    shared_obj.count_char = shared_obj.count_char + 1
    while chr(shared_obj.count_char) in list_to_avoid:
        shared_obj.count_char = shared_obj.count_char + 1
    shared_obj.mapping_dictio[label] = chr(shared_obj.count_char)
