ravioli

Use when writing or modifying a Python function with conditional branches — about to nest an if inside an if, write an else after a branch that returns/raises/continues, or assign a result variable in branches to return at the end.

Use when naming or renaming a Python function, method, or class — especially when a name is heading past three words (ensure_model_file_present, load_and_validate_config), contains and/or/with/if_missing, or describes several steps at once.

Use when writing Python that branches on a value carrying a modeled state — a union of dataclass variants, a Literal-tagged kind/status/type field, or any state-machine state — to choose behavior or a return value, or when adding a variant to such a union. Also when reaching for an if/elif or isinstance chain on a tag field, a hand-rolled exhaustiveness helper, or a dict lookup to consume a tagged union.

Use when composing or chaining dry-python returns Result / FutureResult values — sequencing multi-step operations where each step can fail, recovering from a specific error, or deciding where a Result becomes a plain value, exit code, or response. Also when reaching for .unwrap(), .failure(), ._inner_value, isinstance(r, Success) / is_successful() mid-pipeline, match on Success/Failure outside the consumption edge, Result.do, or try/except around Result-returning code.

Use when converting a value to int, float, str, or bool in Python — about to write int(x), float(x), str(x), bool(x), a bare `if x:` / `x or default` on a value where None, 0, or "" mean different things, or filter(None, xs).

Use when authoring or converting Python type annotations — defining a class / TypedDict / pydantic model / function signature, typing arguments or state, deciding between optional (None / NotRequired) fields and a union, or about to reach for Any, dict[str, Any], cast(), or a type-ignore comment. The minimum modeling rules for typed Python under pyright.

Use when branching off the prefix of a string with str.startswith (namespaced name families like "file.", "edit.", "edit.image.") and the number of prefix branches is growing, when a startswith if-chain is becoming hard to test or extend per-family, or when adding several new prefix families to an existing dispatcher.