Parse address components [roughly] out of a string.

parse_address_str.py

#!/usr/bin/python

def parse_address_str(address):

    parts = {
      'address': '',
      'address2': '',
      'city': '',
      'state': '',
      'zip': ''
    }

    # Try and parse the street address components.
    lines = address.strip().split('\n')
    if len(lines) == 1:
        # Look for a comma between the street and city.
        tokens = lines[0].split(',', 1)
        if len(tokens):
            parts['address'], address = tokens
        else:
            # We could do some really hacky parsing, but maybe it's better to
            # simply return an empty value.
            return parts

    elif len(lines) == 2:
        parts['address'], address = lines
    elif len(lines) == 3:
        parts['address'], parts['address2'], address = lines

    # At this point we assume address contains the city, state, and zip. We now
    # parse those values out.

    address = address.strip()
    # We hope for format like "San Francisco, CA 94105"
    if ',' in address:
        parts['city'], address = address.split(',', 1)
        tokens = address.strip().split()
        if len(tokens):
            # Assume the zip/postal is the last token.
            parts['zip'] = tokens.pop()
            # Treat everything else as the state.
            parts['state'] = ' '.join(tokens)
    else:
        # We hope for format like "San Francisco CA 94105"
        tokens = address.strip().split()
        if len(tokens) >= 3:
            parts['zip'] = tokens.pop()
            parts['state'] = tokens.pop()
            parts['city'] = ' '.join(tokens)
        elif len(tokens):
            for part in ['city', 'state', 'zip']:
                if len(tokens) == 0:
                    break
                parts[part] = token.pop(0)

    return parts

if __name__ == '__main__':
    addys = []
    addys.append('123 Main Street, San Francisco CA 94105')
    addys.append('123 Main Street, San Francisco, CA 94105')
    addys.append("""\
123 Main Street
San Francisco CA 94105
""")
    addys.append("""\
123 Main Street
San Francisco, CA 94105
""")

    import pprint
    pp = pprint.PrettyPrinter(indent=4)
    pp.pprint([parse_address_str(addr) for addr in addys])