How to add documents to the existing index in Whoosh?

To add documents to an existing index in Whoosh, you will need to follow these steps: 

1. First, you will need to open the index using the whoosh.index.open_dir function. This function takes the directory where the index is stored as an argument and returns an Index object:

from whoosh import index

# Open the index
ix = index.open_dir("indexdir")

2. Next, you will need to create a whoosh.writing.IndexWriter object using the Index.writer method. The IndexWriter object allows you to add documents to the index:

# Open an index writer
writer = ix.writer()

3. Now you can use the IndexWriter.add_document method to add documents to the index. The add_document method takes a dictionary of fields and values as an argument. The keys of the dictionary should match the field names in the index's schema, and the values should be the field values:

# Add a document to the index
writer.add_document( title="My Document", body="This is the body of my document.", date="2022-01-01", )  

4. After you have added all the documents you want to add, you will need to call the IndexWriter.commit method to save the changes to the index: 

# Commit the changes
writer.commit()