KeyError — Advanced Playground
Raised when a dictionary key is not found
Python Playground
# Custom exception hierarchy
class DetailedKeyError(KeyError):
def __init__(self, message, details=None):
super().__init__(message)
self.details = details or {}
def __str__(self):
base = super().__str__()
if self.details:
detail_str = ", ".join(f"{k}={v}" for k, v in self.details.items())
return f"{base} [{detail_str}]"
return base
try:
raise DetailedKeyError(
"Something went wrong",
{"code": 42, "source": "test"}
)
except KeyError as e:
print(f"Caught: {e}")
if hasattr(e, 'details'):
print(f"Details: {e.details}")
Output
Click "Run" to execute your code
Custom exception subclasses let you add context and structure to your error handling.
Challenge
Try modifying the code above to explore different behaviors. Can you extend the example to handle a new use case?