implement exceptions

Signed-off-by: ItsNeil17 <[email protected]>

backend/exceptions.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+
+class BackendException(BaseException):
+    """Base exception for all exceptions in this module"""
+
+
+class AccessForbidden(BackendException):
+    def __init__(self, status_code: int) -> None:
+        super().__init__(f"API returned {status_code}")
+
+
+class ValidationError(BackendException):
+    def __init__(self, status_code: int, payload: dict) -> None:
+        self.payload = payload
+        super().__init__(
+            f"API returned {status_code}. This usually occurs to arguments not being specified or the API being unable to process this request. ",
+            payload,
+        )