SentenceWindowNodeParser
SentenceWindowNodeParser
from llama_index.core.node_parser import SentenceWindowNodeParser
parser = SentenceWindowNodeParser.from_defaults(window_size=3)
nodes = parser.get_nodes_from_documents(documents)
print(nodes[0].metadata["window"][:100])检索后用 MetadataReplacementPostProcessor 把命中句替换回窗口文本再送生成，避免模型只看到孤立单句。