入门指南#
默认推荐的文本分割器是 RecursiveCharacterTextSplitter。该文本分割器需要一个字符列表。它尝试根据第一个字符分割创建块,但如果任何块太大,则移动到下一个字符,依此类推。默认情况下,它尝试分割的字符是[" ", "\n", " ", ""]
除了控制可以分割的字符之外,您还可以控制其他一些内容:
-
length_function
: 如何计算块的长度。默认情况下只计算字符数,但通常在此处传递令牌计数器。 -
chunk_size
: 块的最大大小(由长度函数测量)。 -
chunk_overlap
: 不同文本块之间的最大重叠部分。保持文本块之间的一定连续性可能非常有用(例如,使用滑动窗口),因此一些重叠是很好的。
# 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