Getting started with the Dapr client Python SDK

How to get up and running with the Dapr Python SDK

The Dapr client package allows you to interact with other Dapr applications from a Python application.

Pre-requisites

Dapr CLI installed
Initialized Dapr environment
Python 3.7+ installed
Dapr Python module installed

Import the client package

The dapr package contains the DaprClient which will be used to create and use a client.

from dapr.clients import DaprClient

Building blocks

The Python SDK allows you to interface with all of the Dapr building blocks.

Invoke a service

from dapr.clients import DaprClient
with DaprClient() as d:
    # invoke a method (gRPC or HTTP GET)    
    resp = d.invoke_method('service-to-invoke', 'method-to-invoke', data='{"message":"Hello World"}')
    # for other HTTP verbs the verb must be specified
    # invoke a 'POST' method (HTTP only)    
    resp = d.invoke_method('service-to-invoke', 'method-to-invoke', data='{"id":"100", "FirstName":"Value", "LastName":"Value"}', http_verb='post')

For a full guide on service invocation visit How-To: Invoke a service.
Visit Python SDK examples for code samples and instructions to try out service invocation

Save & get application state

from dapr.clients import DaprClient
with DaprClient() as d:
    # Save state
    d.save_state(store_name="statestore", key="key1", value="value1")
    # Get state
    data = d.get_state(store_name="statestore", key="key1").data
    # Delete state
    d.delete_state(store_name="statestore", key="key1")

For a full list of state operations visit How-To: Get & save state.
Visit Python SDK examples for code samples and instructions to try out state management

Query application state (Alpha)

    from dapr import DaprClient
    query = '''
    {
        "filter": {
            "EQ": { "state": "CA" }
        },
        "sort": [
            {
                "key": "person.id",
                "order": "DESC"
            }
        ]
    }
    '''
    with DaprClient() as d:
        resp = d.query_state(
            store_name='state_store',
            query=query,
            states_metadata={"metakey": "metavalue"},  # optional
        )

For a full list of state store query options visit How-To: Query state.
Visit Python SDK examples for code samples and instructions to try out state store querying.

Publish messages

from dapr.clients import DaprClient
with DaprClient() as d:
    resp = d.publish_event(pubsub_name='pubsub', topic_name='TOPIC_A', data='{"message":"Hello World"}')

from cloudevents.sdk.event import v1
from dapr.ext.grpc import App
import json
app = App()
# Default subscription for a topic
@app.subscribe(pubsub_name='pubsub', topic='TOPIC_A')
def mytopic(event: v1.Event) -> None:
    data = json.loads(event.Data())
    print(f'Received: id={data["id"]}, message="{data ["message"]}"' 
          ' content_type="{event.content_type}"',flush=True)
# Specific handler using Pub/Sub routing
@app.subscribe(pubsub_name='pubsub', topic='TOPIC_A',
               rule=Rule("event.type == \"important\"", 1))
def mytopic_important(event: v1.Event) -> None:
    data = json.loads(event.Data())
    print(f'Received: id={data["id"]}, message="{data ["message"]}"' 
          ' content_type="{event.content_type}"',flush=True)

For a full list of state operations visit How-To: Publish & subscribe.
Visit Python SDK examples for code samples and instructions to try out pub/sub

Interact with output bindings

from dapr.clients import DaprClient
with DaprClient() as d:
    resp = d.invoke_binding(binding_name='kafkaBinding', operation='create', data='{"message":"Hello World"}')

For a full guide on output bindings visit How-To: Use bindings.
Visit Python SDK examples for code samples and instructions to try out output bindings

Retrieve secrets

from dapr.clients import DaprClient
with DaprClient() as d:
    resp = d.get_secret(store_name='localsecretstore', key='secretKey')

For a full guide on secrets visit How-To: Retrieve secrets.
Visit Python SDK examples for code samples and instructions to try out retrieving secrets

Get configuration

from dapr.clients import DaprClient
with DaprClient() as d:
    # Get Configuration
    configuration = d.get_configuration(store_name='configurationstore', keys=['orderId'], config_metadata={})

import asyncio
from time import sleep
from dapr.clients import DaprClient
async def executeConfiguration():
    with DaprClient() as d:
        storeName = 'configurationstore'
        key = 'orderId'
        # Wait for sidecar to be up within 20 seconds.
        d.wait(20)
        # Subscribe to configuration by key.
        configuration = await d.subscribe_configuration(store_name=storeName, keys=[key], config_metadata={})
        while True:
            if configuration != None:
                items = configuration.get_items()
                for key, item in items:
                    print(f"Subscribe key={key} value={item.value} version={item.version}", flush=True)
            else:
                print("Nothing yet")
        sleep(5)
asyncio.run(executeConfiguration())

For a full list of state operations visit How-To: Get & save state.
Visit Python SDK examples for code samples and instructions to try out state management