Enums

PostgreSQL enum types become enum.StrEnum classes in a generated enums.py module. Columns of that type are annotated with the class, and values read from the database are coerced into it.

Example

CREATE TYPE test_mood AS ENUM ('sad', 'ok', 'happy', '24h', '_hidden');

generates:

class TestMood(enum.StrEnum):
    SAD = "sad"
    OK = "ok"
    HAPPY = "happy"
    VALUE_24H = "24h"
    VALUE__HIDDEN = "_hidden"

Notice the member names are uppercased, and values that are not valid Python identifiers are sanitized: the digit-leading 24h becomes VALUE_24H and the underscore-leading _hidden becomes VALUE__HIDDEN. The string values are untouched, so round-tripping to the database is exact. See Naming and identifiers for the full sanitization rules.

Using enums

A column of an enum type is annotated with the generated class, and nullable columns get | None:

CREATE TABLE test_enum_types
(
    id   int PRIMARY KEY NOT NULL,
    mood test_mood       NOT NULL,
    maybe_mood test_mood
);

class TestEnumType(msgspec.Struct):
    id_: int
    mood: enums.TestMood
    maybe_mood: enums.TestMood | None

Query functions coerce database values into these classes automatically, so you get real TestMood members back, not bare strings.

Enums in other schemas

Enums in a non-default schema get schema-qualified class names so same-named enums never collide - for example custom.mood becomes CustomMood, distinct from a public.mood that would become Mood.