Enums

Enums are a special kind of type that is restricted to a particular set of values.

For example, we have a few options of ice cream available, and we want to allow user to choose only from those options.

Strawberry supports defining enums using enums from python’s standard library. Here’s a quick tutorial on how to create an enum type in Strawberry:

First, create a new class for the new type, which extends class Enum:

from enum import Enum
 
 
class IceCreamFlavour(Enum): ...

Then, list options as variables in that class:

class IceCreamFlavour(Enum):
    VANILLA = "vanilla"
    STRAWBERRY = "strawberry"
    CHOCOLATE = "chocolate"

Finally we need to register our class as a strawberry type. It's done with the strawberry.enum decorator:

@strawberry.enum
class IceCreamFlavour(Enum):
    VANILLA = "vanilla"
    STRAWBERRY = "strawberry"
    CHOCOLATE = "chocolate"

Note

In some cases you already have an enum defined elsewhere in your code. You can safely use it in your schema and strawberry will generate a default graphql implementation of it.

The only drawback is that it is not currently possible to configure it (documentation / renaming or using strawberry.enum_value on it).

Let’s see how we can use Enums in our schema.

@strawberry.type
class Query:
    @strawberry.field
    def best_flavour(self) -> IceCreamFlavour:
        return IceCreamFlavour.STRAWBERRY

Defining the enum type above would produce this schema in GraphQL:

enum IceCreamFlavour {
  VANILLA
  STRAWBERRY
  CHOCOLATE
}

Here's an example of how you'd use this newly created query:

query {
  bestFlavour
}

Here is result of executed query:

{
  "data": {
    "bestFlavour": "STRAWBERRY"
  }
}

We can also use enums when defining object types (using strawberry.type ). Here is an example of an object that has a field using an Enum:

@strawberry.type
class Cone:
    flavour: IceCreamFlavour
    num_scoops: int
 
 
@strawberry.type
class Query:
    @strawberry.field
    def cone(self) -> Cone:
        return Cone(flavour=IceCreamFlavour.STRAWBERRY, num_scoops=4)

And here's an example of how you'd use this query:

query {
  cone {
    flavour
    numScoops
  }
}

Here is result of executed query:

{
  "data": {
    "cone": {
      "flavour": "STRAWBERRY",
      "numScoops": 4
    }
  }
}

Note

GraphQL types are not a map of name: value, like in python enums. Strawberry uses the name of the members of the enum to create the GraphQL type.

You can also deprecate enum value. To do so you need more verbose syntax using strawberry.enum_value and deprecation_reason . You can mix and match string and verbose syntax.

@strawberry.enum
class IceCreamFlavour(Enum):
    VANILLA = strawberry.enum_value("vanilla")
    CHOCOLATE = "chocolate"
    STRAWBERRY = strawberry.enum_value(
        "strawberry", deprecation_reason="Let's call the whole thing off"
    )