Built-in Exceptions
Exceptions which Python may raise during a program’s execution.
Beginning with Python 1.5, all built-in exceptions are classes. Prior to
1.5, they were strings; to force string exceptions for backward
compatibility, use the -X
command-line option flag. Class exceptions are mostly indistinguishable
from strings, unless concatenated.
Base Classes (Categories)
Exception
Root superclass for all exceptions.
StandardError
Superclass for all other built-in exceptions; a subclass of the
Exception
root class.ArithmeticError
Superclass for
OverflowError
,ZeroDivisionError
,FloatingPointError
; subclass ofStandardError
.LookupError
Superclass for
IndexError
,KeyError
; subclass ofStandardError
.
Specific Exceptions
AssertionError
Raised when an assert statement’s test is false.
AttributeError
On attribute reference or assignment failure.
EOFError
Immediate end-of-file hit by input( ) or raw_input( ).
FloatingPointError
When a floating-point operation fails.
IOError
I/O or file-related operation failure.
ImportError
On failure of import to find module or attribute.
IndexError
On out-of-range sequence offset (fetch or assign).
KeyError
On reference to non-existent mapping key (fetch).
KeyboardInterrupt
On user entry of the interrupt key (often Ctrl-C).
MemoryError
On recoverable memory exhaustion.
NameError
On failure to find a local or global unqualified name.
OverflowError
On excessively large arithmetic operation.
RuntimeError
Obsolete catch-all; define a suitable error instead.
SyntaxError
On parser encountering ...
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