x

libs/core/langchain_core/output_parsers/xml.py

@@ -1,6 +1,6 @@
 import re
+import xml.etree.ElementTree as ET
 from typing import Any, AsyncIterator, Dict, Iterator, List, Optional, Union
-from xml.etree import ElementTree as ET
 
 from langchain_core.exceptions import OutputParserException
 from langchain_core.messages import BaseMessage
@@ -35,10 +35,6 @@ class XMLOutputParser(BaseTransformOutputParser):
         return XML_FORMAT_INSTRUCTIONS.format(tags=self.tags)
 
     def parse(self, text: str) -> Dict[str, List[Any]]:
-        # Imports are temporarily placed here to avoid issue with caching on CI
-        # likely if you're reading this you can move them to the top of the file
-        from defusedxml import ElementTree as DET  # type: ignore[import]
-
         # Try to find XML string within triple backticks
         match = re.search(r"```(xml)?(.*)```", text, re.DOTALL)
         if match is not None:
@@ -50,18 +46,18 @@ class XMLOutputParser(BaseTransformOutputParser):
 
         text = text.strip()
         try:
-            root = DET.fromstring(text)
+            root = ET.fromstring(text)
             return self._root_to_dict(root)
 
-        except (DET.ParseError, DET.EntitiesForbidden) as e:
+        except ET.ParseError as e:
             msg = f"Failed to parse XML format from completion {text}. Got: {e}"
             raise OutputParserException(msg, llm_output=text) from e
 
     def _transform(
         self, input: Iterator[Union[str, BaseMessage]]
     ) -> Iterator[AddableDict]:
-        parser = ET.XMLPullParser(["start", "end"])
         xml_start_re = re.compile(r"<[a-zA-Z:_]")
+        parser = ET.XMLPullParser(["start", "end"])
         xml_started = False
         current_path: List[str] = []
         current_path_has_children = False
@@ -87,7 +83,6 @@ class XMLOutputParser(BaseTransformOutputParser):
             parser.feed(buffer)
             buffer = ""
             # yield all events
-
             for event, elem in parser.read_events():
                 if event == "start":
                     # update current path
@@ -111,11 +106,8 @@ class XMLOutputParser(BaseTransformOutputParser):
         self, input: AsyncIterator[Union[str, BaseMessage]]
     ) -> AsyncIterator[AddableDict]:
         parser = ET.XMLPullParser(["start", "end"])
-        xml_start_re = re.compile(r"<[a-zA-Z:_]")
-        xml_started = False
         current_path: List[str] = []
         current_path_has_children = False
-        buffer = ""
         async for chunk in input:
             if isinstance(chunk, BaseMessage):
                 # extract text
@@ -123,19 +115,8 @@ class XMLOutputParser(BaseTransformOutputParser):
                 if not isinstance(chunk_content, str):
                     continue
                 chunk = chunk_content
-            # add chunk to buffer of unprocessed text
+            # pass chunk to parser
-            buffer += chunk
+            parser.feed(chunk)
-            # if xml string hasn't started yet, continue to next chunk
-            if not xml_started:
-                if match := xml_start_re.search(buffer):
-                    # if xml string has started, remove all text before it
-                    buffer = buffer[match.start() :]
-                    xml_started = True
-                else:
-                    continue
-            # feed buffer to parser
-            parser.feed(buffer)
-            buffer = ""
             # yield all events
             for event, elem in parser.read_events():
                 if event == "start":
@@ -149,10 +130,7 @@ class XMLOutputParser(BaseTransformOutputParser):
                     if not current_path_has_children:
                         yield nested_element(current_path, elem)
                     # prevent yielding of parent element
-                    if current_path:
                     current_path_has_children = True
-                    else:
-                        xml_started = False
         # close parser
         parser.close()