Python 交互

1. Install Dora CLI and Dependencies

First, ensure you have Python 3.11 installed.

Next, install uv if you haven't already:

pip install uv

Then, create and activate a virtual environment:

uv venv --seed -p 3.11
source .venv/bin/activate  # Linux/macOS
.venv\Scripts\activate     # Windows

Finally, install the Dora CLI:

pip install dora-rs-cli

---

2. 建立一个新的数据流(dataflow)

Create a Python-based dataflow and navigate into the project directory:

dora new conversation_py --lang python
cd conversation_py

This creates the following conversation_py directory structure:

├── dataflow.yml
├── listener-1
│   ├── README.md
│   ├── listener_1
│   │   ├── __init__.py
│   │   ├── __main__.py
│   │   └── main.py
│   ├── pyproject.toml
│   └── tests
│       └── test_listener_1.py
└── talker-1
    ├── README.md
    ├── pyproject.toml
    ├── talker_1
    │   ├── __init__.py
    │   ├── __main__.py
    │   └── main.py
    └── tests
        └── test_talker_1.py

---

3. Add another node (optional)

From inside the conversation_py project directory, you can add another node to the workspace:

dora new --kind node talker --lang python

Now open the talker-1/talker_1/main.py file in your text editor.

---

4. 默认节点如何工作

Your node is very bare bones right now. Below is an explanation of how it works by default.

Importing and initializing the node

from dora import Node
import pyarrow as pa

def main():
    node = Node()

Handling input events

for event in node:
    if event["type"] == "INPUT":
        print(
            f"""Node received:
id: {event["id"]},
value: {event["value"]},
metadata: {event["metadata"]}"""
        )

Sending output to another node

node.send_output("speech", pa.array(["Hello World"]))

• send_output sends data to other nodes.
• "speech" is the output ID referenced in the dataflow.
• pa.array(["Hello World"]) creates an Apache Arrow array.
• Metadata is omitted for simplicity in this tutorial.

---

5. Listener node breakdown

File: listener-1/listener_1/main.py

from dora import Node

def main():
    node = Node()
    for event in node:
        if event["type"] == "INPUT":
            message = event["value"][0].as_py()
            print(f"I heard {message} from {event['id']}")

if __name__ == "__main__":
    main()

• event["value"] is an Apache Arrow array.
• [0] accesses the first element.
• .as_py() converts it into a native Python value.

---

6. 运行 数据流(dataflow)

Edit dataflow.yml to connect the nodes:

nodes:
  - id: talker
    path: talker-1/talker_1/main.py
    inputs:
      tick: dora/timer/secs/1
    outputs:
      - speech

  - id: listener
    path: listener-1/listener_1/main.py
    inputs:
      speech: talker/speech

Build and run the dataflow

# Install dependencies
dora build dataflow.yml --uv

# Run the dataflow
dora run dataflow.yml --uv

You should see:

I heard Hello World from speech

To stop the dataflow, press Ctrl+C.

---

7. 结论

Well done reaching the end of this tutorial.
You’ve created and run a Dora dataflow connecting a talker and listener node.

From here, try experimenting with different data types or exploring Dora’s advanced features.