Langchain Load with String

Question

from langchain.document_loaders import TextLoader
# Create the TextLoader object using the file path
Loader = tl('data.txt')

I want to use a langchain with a string instead of a txt file, is this possible?

def get_response(query):
    #print(query)
    result = index.query(query)
    result = str(result)  

Answer 1

Although your question doesn't provide enough information about what you want to achieve; consider that the data for your string must come from somewhere (a PDF file, a URL, a text file, and HTML, a YouTube video etc.).

Having said that, I'll assume that you want to perform a similarity search query on the texts you loaded to retrieve the most relevant texts and output a string. Try this:

from langchain.document_loaders import TextLoader
# Create the TextLoader object using the file path
Loader = tl('data.txt')

document = loader.load()

Here, document is a Document object (all LangChain loaders output this type of object). This Document object is a list, where each list item is a dictionary with two keys: page_content: which is a string, and metadata: which is another dictionary containing information about the document (source, page, URL, etc. they depend on the type of loader you used).

To extract only the text content of document, try this after loading the file:

text_string = document[0].page_content

Then you can use text_string for your downstream processing.

If you want to output the query's result as a string, keep in mind that LangChain retrievers give a Document object as output. Therefore, your function should look like this:

def get_response(query):
    #print(query)
    result = index.query(query)
    result_text = result[0].page_content