Fixes #1164 - Add support for None typehint in Varchar length attribute (#1165)

* Add support for None typehint for length option in Varchar

* fix linter warning

---------

Co-authored-by: Daniel Townsend <[email protected]>

Author: Compro-Prasad

piccolo/apps/user/tables.py

@@ -202,7 +202,9 @@ async def login(cls, username: str, password: str) -> t.Optional[int]:
             The id of the user if a match is found, otherwise ``None``.
 
         """
-        if len(username) > cls.username.length:
+        if (max_username_length := cls.username.length) and len(
+            username
+        ) > max_username_length:
             logger.warning("Excessively long username provided.")
             return None
 

piccolo/columns/column_types.py

@@ -315,7 +315,7 @@ class Band(Table):
 
     def __init__(
         self,
-        length: int = 255,
+        length: t.Optional[int] = 255,
         default: t.Union[str, Enum, t.Callable[[], str], None] = "",
         **kwargs,
     ) -> None: