i hate python 3.8

reflex/state.py

@@ -57,6 +57,7 @@
 from reflex.utils.exceptions import ImmutableStateError, LockExpiredError
 from reflex.utils.exec import is_testing_env
 from reflex.utils.serializers import SerializedType, serialize, serializer
+from reflex.utils.string import remove_prefix
 from reflex.vars import BaseVar, ComputedVar, Var, computed_var
 
 if TYPE_CHECKING:
@@ -1175,9 +1176,9 @@ def get_substate(self, path: Sequence[str] | Type[S]) -> BaseState | S:
             ValueError: If the substate is not found.
         """
         if isinstance(path, type):
-            path = (
-                path.get_full_name().removeprefix(f"{self.get_full_name()}.").split(".")
-            )
+            path = remove_prefix(
+                text=path.get_full_name(), prefix=f"{self.get_full_name()}."
+            ).split(".")
         if len(path) == 0:
             return self
         if path[0] == self.get_name():

reflex/utils/string.py

@@ -0,0 +1,21 @@
+"""String utility functions."""
+
+import sys
+
+
+def remove_prefix(text: str, prefix: str) -> str:
+    """Remove a prefix from a string, if present.
+    This can be removed once we drop support for Python 3.8.
+
+    Args:
+        text: The string to remove the prefix from.
+        prefix: The prefix to remove.
+
+    Returns:
+        The string with the prefix removed, if present.
+    """
+    if sys.version_info >= (3, 9):
+        return text.removeprefix(prefix)
+    if text.startswith(prefix):
+        return text[len(prefix) :]
+    return text