diff --git a/flair/data_fetcher.py b/flair/data_fetcher.py
index bf055f7b8c..fdd2e4da62 100644
--- a/flair/data_fetcher.py
+++ b/flair/data_fetcher.py
@@ -570,7 +570,7 @@ def read_column_data(
                 sentence: Sentence = Sentence()
 
             else:
-                fields: List[str] = re.split("\s+", line)
+                fields: List[str] = re.split(r"\s+", line)
                 token = Token(fields[text_column])
                 for column in column_name_map:
                     if len(fields) > column:
diff --git a/flair/datasets/sequence_labeling.py b/flair/datasets/sequence_labeling.py
index e08f777636..a5dea613d7 100644
--- a/flair/datasets/sequence_labeling.py
+++ b/flair/datasets/sequence_labeling.py
@@ -21,7 +21,7 @@ def __init__(
             test_file=None,
             dev_file=None,
             tag_to_bioes=None,
-            column_delimiter: str = "\s+",
+            column_delimiter: str = r"\s+",
             comment_symbol: str = None,
             encoding: str = "utf-8",
             document_separator_token: str = None,
@@ -103,7 +103,7 @@ def __init__(
             path_to_column_file: Union[str, Path],
             column_name_map: Dict[int, str],
             tag_to_bioes: str = None,
-            column_delimiter: str = "\s+",
+            column_delimiter: str = r"\s+",
             comment_symbol: str = None,
             in_memory: bool = True,
             document_separator_token: str = None,
diff --git a/flair/trainers/language_model_trainer.py b/flair/trainers/language_model_trainer.py
index 97679138e3..27968b3bf3 100644
--- a/flair/trainers/language_model_trainer.py
+++ b/flair/trainers/language_model_trainer.py
@@ -143,9 +143,9 @@ def charsplit(
     @staticmethod
     def random_casechange(line: str) -> str:
         no = random.randint(0, 99)
-        if no is 0:
+        if no == 0:
             line = line.lower()
-        if no is 1:
+        if no == 1:
             line = line.upper()
         return line