Python 3.13+Exceptionsexception

_IncompleteInputError

built-in exceptions

Internal: source is syntactically incomplete (used by the REPL for multi-line input).

Syntax

raise _IncompleteInputError

The leading underscore marks it as CPython plumbing: the interpreter uses it to tell "the source simply ran out mid-construct" apart from a real syntax error, so the interactive prompt asks for a continuation line instead of reporting a failure. It is a subclass of SyntaxError, so a plain except SyntaxError already covers it. Do not reference the name in your own code — private names come and go between versions without notice.

Examples

try:
    raise _IncompleteInputError
except _IncompleteInputError as e:
    print(type(e).__name__)   # → _IncompleteInputError

See also

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