pydase/docs/user-guide/interaction/Python Client.md
2025-02-20 17:28:07 +01:00

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# Python RPC Client
The [`pydase.Client`][pydase.Client] allows you to connect to a remote `pydase` service using socket.io, facilitating interaction with the service as though it were running locally.
## Basic Usage
```python
import pydase
# Replace <ip_addr> and <service_port> with the appropriate values for your service
client_proxy = pydase.Client(url="ws://<ip_addr>:<service_port>").proxy
# For SSL-encrypted services, use the wss protocol
# client_proxy = pydase.Client(url="wss://your-domain.ch").proxy
# Interact with the service attributes as if they were local
client_proxy.voltage = 5.0
print(client_proxy.voltage) # Expected output: 5.0
```
This example shows how to set and retrieve the `voltage` attribute through the client proxy.
The proxy acts as a local representation of the remote service, enabling intuitive interaction.
The proxy class automatically synchronizes with the server's attributes and methods, keeping itself up-to-date with any changes. This dynamic synchronization essentially mirrors the server's API, making it feel like you're working with a local object.
## Context Manager Support
You can also use the client within a context manager, which automatically handles connection management (i.e., opening and closing the connection):
```python
import pydase
with pydase.Client(url="ws://localhost:8001") as client:
client.proxy.my_method()
```
Using the context manager ensures that connections are cleanly closed once the block of code finishes executing.
## Tab Completion Support
In interactive environments like Python interpreters or Jupyter notebooks, the proxy supports tab completion. This allows users to explore available methods and attributes.
## Integrating the Client into Another Service
You can integrate a `pydase` client proxy within another service. Here's an example of how to set this up:
```python
import pydase
class MyService(pydase.DataService):
proxy = pydase.Client(
url="ws://<ip_addr>:<service_port>",
block_until_connected=False,
client_id="my_pydase_client_id",
).proxy
# For SSL-encrypted services, use the wss protocol
# proxy = pydase.Client(
# url="wss://your-domain.ch",
# block_until_connected=False,
# client_id="my_pydase_client_id",
# ).proxy
if __name__ == "__main__":
service = MyService()
# Create a server that exposes this service
server = pydase.Server(service, web_port=8002).run()
```
In this example:
- The `MyService` class has a `proxy` attribute that connects to a `pydase` service at `<ip_addr>:<service_port>`.
- By setting `block_until_connected=False`, the service can start without waiting for the connection to succeed, which is particularly useful in distributed systems where services may initialize in any order.
- By setting `client_id`, the server will provide more accurate logs of the connecting client. If set, this ID is sent as `X-Client-Id` header in the HTTP(s) request.
## Custom `socketio.AsyncClient` Connection Parameters
You can also configure advanced connection options by passing additional arguments to the underlying [`AsyncClient`][socketio.AsyncClient] via `sio_client_kwargs`. This allows you to fine-tune reconnection behaviour, delays, and other settings:
```python
client = pydase.Client(
url="ws://localhost:8001",
sio_client_kwargs={
"reconnection_attempts": 3,
"reconnection_delay": 2,
"reconnection_delay_max": 10,
}
).proxy
```
In this setup, the client will attempt to reconnect three times, with an initial delay of 2 seconds (each successive attempt doubles this delay) and a maximum delay of 10 seconds between attempts.