Implement exception holder

pytchat/core/pytchat.py

@@ -42,6 +42,10 @@ class PytchatCore:
     topchat_only : bool
         If True, get only top chat.
 
+    hold_exception : bool [default:True]
+        If True, when exceptions occur, the exception is holded internally,
+        and can be raised by raise_for_status().
+
     Attributes
     ---------
     _is_alive : bool
@@ -56,7 +60,8 @@ class PytchatCore:
                  interruptable=True,
                  force_replay=False,
                  topchat_only=False,
-                 logger=config.logger(__name__)
+                 hold_exception=True,
+                 logger=config.logger(__name__),
                  ):
         self._video_id = extract_video_id(video_id)
         self.seektime = seektime
@@ -66,12 +71,16 @@ class PytchatCore:
             self.processor = processor
         self._is_alive = True
         self._is_replay = force_replay
-        self._parser = Parser(is_replay=self._is_replay)
+        self._hold_exception = hold_exception
+        self._exception_holder = None
+        self._parser = Parser(
+            is_replay=self._is_replay,
+            exception_holder=self._exception_holder
+        )
         self._first_fetch = True
         self._fetch_url = "live_chat/get_live_chat?continuation="
         self._topchat_only = topchat_only
         self._logger = logger
-        self.exception = None
         if interruptable:
             signal.signal(signal.SIGINT, lambda a, b: self.terminate())
         self._setup()
@@ -108,13 +117,13 @@ class PytchatCore:
                     return chat_component
         except exceptions.ChatParseException as e:
             self._logger.debug(f"[{self._video_id}]{str(e)}")
-            raise
+            self._raise_exception(e)
-        except (TypeError, json.JSONDecodeError):
+        except (TypeError, json.JSONDecodeError) as e:
             self._logger.error(f"{traceback.format_exc(limit=-1)}")
-            raise
+            self._raise_exception(e)
 
         self._logger.debug(f"[{self._video_id}]finished fetching chat.")
-        raise exceptions.ChatDataFinished
+        self._raise_exception(exceptions.ChatDataFinished)
 
     def _get_contents(self, continuation, client, headers):
         '''Get 'continuationContents' from livechat json.
@@ -167,7 +176,7 @@ class PytchatCore:
         else:
             self._logger.error(f"[{self._video_id}]"
                                f"Exceeded retry count. Last error: {str(err)}")
-            raise exceptions.RetryExceedMaxCount()
+            self._raise_exception(exceptions.RetryExceedMaxCount())
         return livechat_json
     
     def get(self):
@@ -188,5 +197,11 @@ class PytchatCore:
         self.processor.finalize()
 
     def raise_for_status(self):
-        if self.exception is not None:
+        if self._exception_holder is not None:
-            raise self.exception
+            raise self._exception_holder
+
+    def _raise_exception(self, exception: Exception = None):
+        self._is_alive = False
+        if self._hold_exception is False:
+            raise exception
+        self._exception_holder = exception

pytchat/parser/live.py

@@ -8,15 +8,26 @@ from .. import exceptions
 
 
 class Parser:
+    '''
+    Parser of chat json.
+    
+    Parameter
+    ----------
+    is_replay : bool
 
-    __slots__ = ['is_replay']
+    exception_holder : Object [default:Npne]
+        The object holding exceptions.
+        This is passed from the parent livechat object.
+    '''
+    __slots__ = ['is_replay', 'exception_holder']
 
-    def __init__(self, is_replay):
+    def __init__(self, is_replay, exception_holder=None):
         self.is_replay = is_replay
+        self.exception_holder = exception_holder
 
     def get_contents(self, jsn):
         if jsn is None:
-            raise exceptions.IllegalFunctionCall('Called with none JSON object.')
+            self.raise_exception(exceptions.IllegalFunctionCall('Called with none JSON object.'))
         if jsn['response']['responseContext'].get('errors'):
             raise exceptions.ResponseContextError(
                 'The video_id would be wrong, or video is deleted or private.')
@@ -42,11 +53,11 @@ class Parser:
 
         if contents is None:
             '''Broadcasting end or cannot fetch chat stream'''
-            raise exceptions.NoContents('Chat data stream is empty.')
+            self.raise_exception(exceptions.NoContents('Chat data stream is empty.'))
 
         cont = contents['liveChatContinuation']['continuations'][0]
         if cont is None:
-            raise exceptions.NoContinuation('No Continuation')
+            self.raise_exception(exceptions.NoContinuation('No Continuation'))
         metadata = (cont.get('invalidationContinuationData')
                     or cont.get('timedContinuationData')
                     or cont.get('reloadContinuationData')
@@ -54,13 +65,13 @@ class Parser:
                     )
         if metadata is None:
             if cont.get("playerSeekContinuationData"):
-                raise exceptions.ChatDataFinished('Finished chat data')
+                self.raise_exception(exceptions.ChatDataFinished('Finished chat data'))
             unknown = list(cont.keys())[0]
             if unknown:
-                raise exceptions.ReceivedUnknownContinuation(
+                self.raise_exception(exceptions.ReceivedUnknownContinuation(
-                    f"Received unknown continuation type:{unknown}")
+                    f"Received unknown continuation type:{unknown}"))
             else:
-                raise exceptions.FailedExtractContinuation('Cannot extract continuation data')
+                self.raise_exception(exceptions.FailedExtractContinuation('Cannot extract continuation data'))
         return self._create_data(metadata, contents)
 
     def reload_continuation(self, contents):
@@ -72,7 +83,7 @@ class Parser:
         """
         if contents is None:
             '''Broadcasting end or cannot fetch chat stream'''
-            raise exceptions.NoContents('Chat data stream is empty.')
+            self.raise_exception(exceptions.NoContents('Chat data stream is empty.'))
         cont = contents['liveChatContinuation']['continuations'][0]
         if cont.get("liveChatReplayContinuationData"):
             # chat data exist.
@@ -81,7 +92,7 @@ class Parser:
         init_cont = cont.get("playerSeekContinuationData")
         if init_cont:
             return init_cont.get("continuation")
-        raise exceptions.ChatDataFinished('Finished chat data')
+        self.raise_exception(exceptions.ChatDataFinished('Finished chat data'))
 
     def _create_data(self, metadata, contents):
         actions = contents['liveChatContinuation'].get('actions')
@@ -103,3 +114,8 @@ class Parser:
         start = int(actions[0]["replayChatItemAction"]["videoOffsetTimeMsec"])
         last = int(actions[-1]["replayChatItemAction"]["videoOffsetTimeMsec"])
         return (last - start)
+
+    def raise_exception(self, exception):
+        if self.exception_holder is None:
+            raise exception
+        self.exception_holder = exception