def __lambda_values__(string):
    """
    Extracts the wavelength information from the string.

    :param string: A part of the HTML-code from a SVO filter web-page
    :type string: str
    :return: The float value of the string
    :rtype: float
    """
    lambda_value = string.split('<td')[2]
    lambda_value = lambda_value.split('</td>')[0]
    lambda_value = lambda_value.split('>')[-1]
    lambda_value = float(lambda_value)
    return lambda_value
