aws-powertools/powertools-lambda-python v1.7.0

v.1.7.0

on GitHub

from aws_lambda_powertools.utilities.parser import event_parser, BaseModel, ValidationError
from aws_lambda_powertools.utilities.typing import LambdaContext

import json

class OrderItem(BaseModel):
    id: int
    quantity: int
    description: str

class Order(BaseModel):
    id: int
    description: str
    items: List[OrderItem] # nesting models are supported
    optional_field: Optional[str] # this field may or may not be available when parsing


@event_parser(model=Order)
def handler(event: Order, context: LambdaContext):
    assert event.id == 10876546789
    assert event.description == "My order"
    assert len(event.items) == 1

    order_items = [items for item in event.items]
    ...

payload = {
    "id": 10876546789,
    "description": "My order",
    "items": [
        {
            "id": 1015938732,
            "quantity": 1,
            "description": "item xpto"
        }
    ]
}

handler(event=payload, context=LambdaContext())
# also works if event is a JSON string
handler(event=json.dumps(payload), context=LambdaContext()) 

from aws_lambda_powertools.utilities.parser import parse, BaseModel
from aws_lambda_powertools.utilities.parser.models import EventBridgeModel

from typing import List, Optional

class OrderItem(BaseModel):
    id: int
    quantity: int
    description: str

class Order(BaseModel):
    id: int
    description: str
    items: List[OrderItem]

# Override `detail` key of a custom event in EventBridge from str to Order
class OrderEventModel(EventBridgeModel):
    detail: Order

payload = {...} # EventBridge event dict with Order inside detail as JSON 
order = parse(model=OrderEventModel, event=payload) # parse input event into OrderEventModel

assert order.source == "OrderService"
assert order.detail.description == "My order"
assert order.detail_type == "OrderPurchased" # we rename it to snake_case since detail-type is an invalid name

# We can access our Order just as fine now
for order_item in order.detail.items:
    ...

# We can also serialize any property of our parsed model into JSON, JSON Schema, or as a Dict
order_dict = order.dict()
order_json = order.json()
order_json_schema_as_dict = order.schema()
order_json_schema_as_json = order.schema_json(indent=2)

from aws_lambda_powertools.utilities.parser import event_parser, parse, BaseModel, envelopes
from aws_lambda_powertools.utilities.typing import LambdaContext

class UserModel(BaseModel):
    username: str
    password1: str
    password2: str

payload = {
    "version": "0",
    "id": "6a7e8feb-b491-4cf7-a9f1-bf3703467718",
    "detail-type": "CustomerSignedUp",
    "source": "CustomerService",
    "account": "111122223333",
    "time": "2020-10-22T18:43:48Z",
    "region": "us-west-1",
    "resources": ["some_additional_"],
    "detail": {
        "username": "universe",
        "password1": "myp@ssword",
        "password2": "repeat password"
    }
}

ret = parse(model=UserModel, envelope=envelopes.EventBridgeModel, event=payload)

# Parsed model only contains our actual model, not the entire EventBridge + Payload parsed
assert ret.password1 == ret.password2

# Same behaviour but using our decorator
@event_parser(model=UserModel, envelope=envelopes.EventBridgeModel)
def handler(event: UserModel, context: LambdaContext):
    assert event.password1 == event.password2