递归字符分割器

这个文本分割器是用于通用文本的推荐分割器。它通过一个字符列表进行参数化。它按照顺序尝试在这些字符上进行分割，直到分块足够小为止。默认的字符列表是 ["\n\n", "\n", " ", ""]。这样做的效果是尽可能地保持段落（然后是句子，然后是单词）在一起，因为它们在语义上通常是最相关的文本片段。

文本如何进行分割：根据字符列表进行分割。
分块大小的测量方式：按字符数量进行测量。

# This is a long document we can split up.
with open('../../../state_of_the_union.txt') as f:
    state_of_the_union = f.read()

from langchain.text_splitter import RecursiveCharacterTextSplitter

text_splitter = RecursiveCharacterTextSplitter(
    # Set a really small chunk size, just to show.
    chunk_size = 100,
    chunk_overlap  = 20,
    length_function = len,
)

texts = text_splitter.create_documents([state_of_the_union])
print(texts[0])
print(texts[1])

page_content='Madam Speaker, Madam Vice President, our First Lady and Second Gentleman. Members of Congress and' lookup_str='' metadata={} lookup_index=0 page_content='of Congress and the Cabinet. Justices of the Supreme Court. My fellow Americans.' lookup_str='' metadata={} lookup_index=0

text_splitter.split_text(state_of_the_union)[:2]

['Madam Speaker, Madam Vice President, our First Lady and Second Gentleman. Members of Congress and', 'of Congress and the Cabinet. Justices of the Supreme Court. My fellow Americans.']

# 递归字符分割器

递归字符分割器