main.py

from documentcloud.addon import AddOn
from documentcloud.exceptions import APIError
from requests.exceptions import RequestException
from documentcloud.addon import SoftTimeOutAddOn

class ExtractAndTag(SoftTimeOutAddOn):
    """Add-On that extracts text between a start and end string"""
    def main(self):
        self.set_message("Extracting text from documents...")
        start = self.data.get('start').strip()
        end = self.data.get('end').strip()
        name_key = self.data.get("key_name").strip()
        for document in self.get_documents():
            text_to_parse = document.full_text
            text_to_parse = text_to_parse.replace("\n", " ")
            start_char = text_to_parse.find(start) + len(start)
            end_char = text_to_parse.find(end)
            extracted_text = text_to_parse[start_char:end_char]
            try:
                document.data[name_key] = extracted_text
                document.save()
            except (APIError, RequestException) as exc:
                print("Tagging Error on Document", str(exc))
                print(document.title)
        self.set_message("Add-On run complete.")
if __name__ == "__main__":
    ExtractAndTag().main()