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Python Built-in Exceptions

Python 3.1275 codes

Built-in exceptions, warnings, and stdlib errors

Showing 75 of 75 errors

Code	Message	Severity	Tier
SyntaxError	Invalid syntax	ERROR	Common	→
IndentationError	Incorrect indentation	ERROR	Common	→
NameError	Name not found in local or global scope	ERROR	Notable	→
TypeError	Operation applied to object of wrong type	ERROR	Notable	→
ValueError	Function argument has right type but inappropriate value	ERROR	Critical	→
AttributeError	Object does not have the specified attribute	ERROR	Notable	→
KeyError	Dictionary key not found	ERROR	Notable	→
IndexError	Sequence index out of range	ERROR	Notable	→
ImportError	Could not import module or member	ERROR		→
ModuleNotFoundError	Module not found	ERROR		→
OSError	Operating system-related error	ERROR		→
FileNotFoundError	File or directory not found	ERROR	Critical	→
PermissionError	Operation not permitted	ERROR		→
RuntimeError	Error doesn't fall in other categories	ERROR	Critical	→
RecursionError	Maximum recursion depth exceeded	ERROR	Critical	→
StopIteration	Iterator has no more items	INFO	Common	→
GeneratorExit	Generator's close() method was called	INFO	Notable	→
SystemExit	Program exited (sys.exit() called)	INFO	Notable	→
KeyboardInterrupt	User pressed Ctrl+C	INFO	Notable	→
MemoryError	Operation ran out of memory	CRITICAL		→
OverflowError	Result of an arithmetic operation is too large to be represented	ERROR	Critical	→
ZeroDivisionError	Division or modulo by zero	ERROR	Notable	→
UnicodeDecodeError	Unicode decoding error	ERROR	Critical	→
UnicodeEncodeError	Unicode encoding error	ERROR	Critical	→
AssertionError	Assertion statement failed	ERROR	Notable	→
NotImplementedError	Abstract method not implemented	ERROR	Notable	→
TimeoutError	Operation timed out	ERROR		→
ConnectionError	Connection-related error	ERROR		→
BrokenPipeError	Pipe is broken	ERROR		→
IsADirectoryError	Operation expected a file, but got a directory	ERROR	Critical	→
EOFError	End of file reached	ERROR	Notable	→
UnboundLocalError	Local variable referenced before assignment	ERROR	Notable	→
FloatingPointError	Floating-point operation failed	ERROR	Notable	→
BufferError	Buffer operation failed	ERROR	Notable	→
StopAsyncIteration	Async iterator exhausted	INFO	Common	→
BlockingIOError	Non-blocking I/O would block	ERROR	Notable	→
ChildProcessError	Child process operation failed	ERROR	Notable	→
ConnectionAbortedError	Connection aborted by peer	ERROR	Notable	→
ConnectionRefusedError	Connection refused by server	ERROR	Notable	→
ConnectionResetError	Connection reset by peer	ERROR	Notable	→
FileExistsError	File or directory already exists	ERROR	Common	→
InterruptedError	System call interrupted by signal	ERROR	Notable	→
NotADirectoryError	Not a directory	ERROR	Common	→
ProcessLookupError	Process not found	ERROR	Notable	→
ReferenceError	Weak reference expired	ERROR	Notable	→
SystemError	Internal Python interpreter error	CRITICAL		→
TabError	Inconsistent use of tabs and spaces	ERROR	Common	→
UnicodeTranslateError	Unicode translation failed	ERROR	Notable	→
ExceptionGroup	Multiple exceptions raised simultaneously	ERROR	Critical	→
DeprecationWarning	Deprecated feature used	WARNING	Common	→
ResourceWarning	Unclosed resource	WARNING	Notable	→
RuntimeWarning	Suspicious runtime behaviour	WARNING	Notable	→
UserWarning	User-issued warning	WARNING	Common	→
json.JSONDecodeError	Invalid JSON	ERROR	Notable	→
subprocess.CalledProcessError	Called process returned non-zero exit code	ERROR	Notable	→
subprocess.TimeoutExpired	Subprocess timed out	ERROR	Notable	→
re.error	Invalid regular expression	ERROR	Notable	→
asyncio.CancelledError	Async task was cancelled	WARNING	Notable	→
ssl.SSLError	TLS/SSL certificate or handshake error	ERROR	Critical	→
pickle.PicklingError	Object cannot be pickled	ERROR	Notable	→
struct.error	Binary struct pack/unpack failed	ERROR	Notable	→
io.UnsupportedOperation	I/O operation not supported	ERROR	Common	→
EncodingWarning	Locale or encoding mismatch detected	WARNING	Common	→
FutureWarning	Behaviour will change in a future Python release	WARNING	Common	→
PendingDeprecationWarning	Feature may be deprecated in a future release	WARNING	Common	→
ImportWarning	Probable mistake in module import	WARNING	Common	→
SyntaxWarning	Dubious or potentially invalid syntax	WARNING	Common	→
UnicodeWarning	Unicode comparison or conversion issue	WARNING	Common	→
BytesWarning	Bytes or buffer compared with str	WARNING	Common	→
BaseExceptionGroup	Group of BaseException instances (Python 3.11+)	ERROR	Notable	→
urllib.error.URLError	URL request failed — network or DNS error	ERROR	Notable	→
http.client.HTTPException	Low-level HTTP protocol error	ERROR	Notable	→
csv.Error	CSV parsing or writing error	ERROR	Common	→
zipfile.BadZipFile	ZIP file is corrupt or not a valid ZIP	ERROR	Common	→
socket.error	Socket-level network error (alias for OSError)	ERROR	Notable	→