import re


def normalize_name(n):
    """
    Normalize street name.

    The names of many streets are spelled slightly different in our
    different data sources. This function tries to reduce these
    differences.
    """
    n = (n.replace('St.', 'sankt')
          .lower()
          .replace('-', '')
          .replace('ß', 'ss')
          .strip())
    return re.sub(r'\s+', ' ', n)