def normalize_url(url):
    """Return a normalized url with trailing and without leading slash.

     >>> normalize_url(None)
     '/'
     >>> normalize_url('/')
     '/'
     >>> normalize_url('/foo/bar')
     '/foo/bar'
     >>> normalize_url('foo/bar')
     '/foo/bar'
     >>> normalize_url('/foo/bar/')
     '/foo/bar'
    """
    if not url or len(url) == 0:
        return '/'
    if not url.startswith('/'):
        url = '/' + url
    if len(url) > 1 and url.endswith('/'):
        url = url[0:len(url) - 1]
    return url
dataset/ETHPy150Open batiste/django-page-cms/pages/utils.py/normalize_url/original