8. Action Iterable
BaseIterableAction returns a synchronous iterable. Here both actions return generators, so greeting objects are produced as the caller consumes the returned iterable.
Run from the repository root:
Source
"""BaseIterableAction — lazy sync iterable (generator). Class and function styles."""
import asyncio
from collections.abc import Iterable
from fastsprout.core.action import BaseIterableAction
from fastsprout.core.fields import Field
from fastsprout.core.schema import BaseSchema
class GreetBatchIn(BaseSchema):
name: Field[str]
times: Field[int]
class GreetOut(BaseSchema):
message: Field[str]
class GreetBatch(BaseIterableAction[GreetBatchIn, GreetOut]):
async def __call__(self, payload: GreetBatchIn, /) -> Iterable[GreetOut]:
return (
GreetOut(message=f"hello, {payload.name} #{i}")
for i in range(payload.times)
)
async def greet_batch(payload: GreetBatchIn, /) -> Iterable[GreetOut]:
return (
GreetOut(message=f"hello, {payload.name} #{i}")
for i in range(payload.times)
)
async def main() -> None:
payload = GreetBatchIn(name="world", times=3)
assert isinstance(GreetBatch(), BaseIterableAction)
assert isinstance(greet_batch, BaseIterableAction)
print([g.message for g in await GreetBatch()(payload)])
print([g.message for g in await greet_batch(payload)])
if __name__ == "__main__":
asyncio.run(main())
Result
Consuming either generator yields the same three messages: