def slice_dict(original_dict, key_string):
    """
    :param original_dict: Original (and larger) dictionary with all entrances
    :param key_string: key string (desired starting string)
    :return: A new dictionary with all the entrances of the original that start with key_string
    """
    newdict = {}

    for key in original_dict:
        if key.startswith(key_string):
            newdict[key] = original_dict[key]

    return newdict