Add optional error code to exceptions (#585)

kasa/exceptions.py

@@ -1,10 +1,15 @@
 """python-kasa exceptions."""
 from enum import IntEnum
+from typing import Optional
 
 
 class SmartDeviceException(Exception):
     """Base exception for device errors."""
 
+    def __init__(self, *args, error_code: Optional["SmartErrorCode"] = None):
+        self.error_code = error_code
+        super().__init__(args)
+
 
 class UnsupportedDeviceException(SmartDeviceException):
     """Exception for trying to connect to unsupported devices."""
@@ -17,14 +22,23 @@ class UnsupportedDeviceException(SmartDeviceException):
 class AuthenticationException(SmartDeviceException):
     """Base exception for device authentication errors."""
 
+    def __init__(self, *args, error_code: Optional["SmartErrorCode"] = None):
+        super().__init__(args, error_code)
+
 
 class RetryableException(SmartDeviceException):
     """Retryable exception for device errors."""
 
+    def __init__(self, *args, error_code: Optional["SmartErrorCode"] = None):
+        super().__init__(args, error_code)
+
 
 class TimeoutException(SmartDeviceException):
     """Timeout exception for device errors."""
 
+    def __init__(self, *args, error_code: Optional["SmartErrorCode"] = None):
+        super().__init__(args, error_code)
+
 
 class SmartErrorCode(IntEnum):
     """Enum for SMART Error Codes."""