Returns the value of a keypath in a dictionary
    if the keypath exists or None if the keypath
    does not exist.

def value_for_keypath(dict, keypath):
    """
    Returns the value of a keypath in a dictionary
    if the keypath exists or None if the keypath
    does not exist.
    """

    if len(keypath) == 0:
        return dict

    keys = keypath.split('.')
    value = dict
    for key in keys:
        if key in value:
            value = value[key]
        else:
            return None

    return value