def to_python(self, value):

        def split_url(url):
            """
            Returns a list of url parts via ``urlparse.urlsplit`` (or raises a
            ``ValidationError`` exception for certain).
            """
            try:
                return list(urlsplit(url))
            except __HOLE__:
                # urlparse.urlsplit can raise a ValueError with some
                # misformatted URLs.
                raise ValidationError(self.error_messages['invalid'], code='invalid')

        value = super(URLField, self).to_python(value)
        if value:
            url_fields = split_url(value)
            if not url_fields[0]:
                # If no URL scheme given, assume http://
                url_fields[0] = 'http'
            if not url_fields[1]:
                # Assume that if no domain is provided, that the path segment
                # contains the domain.
                url_fields[1] = url_fields[2]
                url_fields[2] = ''
                # Rebuild the url_fields list, since the domain segment may now
                # contain the path too.
                url_fields = split_url(urlunsplit(url_fields))
            value = urlunsplit(url_fields)
        return value
dataset/ETHPy150Open django/django/django/forms/fields.py/URLField.to_python