diff --git a/sktalk/corpus/corpus.py b/sktalk/corpus/corpus.py
index 77f07f1..2bab4ab 100644
--- a/sktalk/corpus/corpus.py
+++ b/sktalk/corpus/corpus.py
@@ -10,7 +10,8 @@ def __init__(
         self._conversations = conversations or []
         for conversation in self._conversations:
             if not isinstance(conversation, Conversation):
-                raise TypeError("All conversations should be of type Conversation")
+                raise TypeError(
+                    "All conversations should be of type Conversation")
         self._metadata = metadata
 
     def __add__(self, other: "Corpus") -> "Corpus":
@@ -26,7 +27,8 @@ def append(self, conversation: Conversation):
         if isinstance(conversation, Conversation):
             self._conversations.append(conversation)
         else:
-            raise TypeError("Conversations added should be of type Conversation")
+            raise TypeError(
+                "Conversations added should be of type Conversation")
 
     def return_json(self):
         self.return_dataframe()
diff --git a/sktalk/corpus/parsing/cha.py b/sktalk/corpus/parsing/cha.py
index 711befc..7027412 100644
--- a/sktalk/corpus/parsing/cha.py
+++ b/sktalk/corpus/parsing/cha.py
@@ -8,7 +8,7 @@
 class ChaFile(InputFile):
     def _pla_reader(self) -> pylangacq.Reader:
         return pylangacq.read_chat(self._path)
-    
+
     def parse(self):
         """Parse conversation file in Chat format
 
@@ -36,7 +36,6 @@ def _to_utterance(chat_utterance) -> Utterance:
     def _extract_metadata(self):
         return self._pla_reader().headers()[0]
 
-
     @staticmethod
     def _split_time(time):
         if time is None:
diff --git a/sktalk/corpus/parsing/parser.py b/sktalk/corpus/parsing/parser.py
index 281f1d9..039b05e 100644
--- a/sktalk/corpus/parsing/parser.py
+++ b/sktalk/corpus/parsing/parser.py
@@ -20,10 +20,10 @@ def metadata(self):
         if metadata.keys().isdisjoint(self._metadata):
             return self._metadata | metadata
         raise ValueError("Duplicate key in the metadata")
-    
+
     def _extract_metadata(self):
         return {}
-            
+
     @staticmethod
     def _to_timestamp(time_ms):
         try: