def excise(dict_, keypath):
    """
    Remove key pointed at by ``keypath`` from nested dict ``dict_``, if exists.

    .. versionadded:: 1.0
    """
    data = dict_
    keypath = list(keypath)
    leaf_key = keypath.pop()
    while keypath:
        key = keypath.pop(0)
        if key not in data:
            return
        data = data[key]
    if leaf_key in data:
        del data[leaf_key]
