# libtmux._internal.query_list.OpNotFound

- **Module:** libtmux._internal.query_list
- **Package:** libtmux
- **Language:** Python
- **Kind:** exception
- **Source:** https://github.com/tmux-python/libtmux/blob/9fdd083a8181a827889337b63cd4e6daea661a8c/src/libtmux/_internal/query_list.py#L322
- **Page:** https://libtmux.org/en/py/latest/reference/libtmux-_internal-query_list-opnotfound/

Raised when a filter names a lookup that does not exist.

The lookup is the part after the last ``__`` in a keyword, so a mistyped
one — or a field name that happens to end in ``__`` — reaches here rather
than silently matching nothing.

## Members

- `__init__` (method)