import re


def make_shp_filename(place_name):
    """
    Create a filename string in a consistent format from a place name string.
    
    Parameters
    ----------
    place_name : string, place name to convert into a filename
    
    Returns
    -------
    filename : string
    """
    name_pieces = list(reversed(place_name.split(', ')))
    filename = '-'.join(name_pieces).lower().replace(' ','_')
    filename = re.sub('[^0-9a-zA-Z_-]+', '', filename)
    return filename