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Using the Python language module

The Python Language Module for Thymis allows you to write and run Python code on your devices directly from the Thymis UI — including dependency handling, service setup, and timer configuration — without dropping into a custom Nix expression.

How to Use the Python Module

  1. Add the module: In your device or tag configuration, add the “Python Module” from the module list.

  2. Configure your script: Write your Python code directly in the “Python Script” field.

  3. Set dependencies: Add any required Python packages from python3Packages (e.g., requests, numpy, pandas).

  4. Add system packages: Include any system packages from nixpkgs if needed (e.g., git, curl, ffmpeg).

  5. Configure timing: Use the timer configuration to control when and how often your script runs.

Module Settings

SettingTypePurpose
Timer ConfigurationSystemdTimerControls when the script runs (oneshot, recurring, etc.)
Python PackagesListPython packages from python3Packages to include
System PackagesListSystem packages from nixpkgs to include in PATH
Python ScriptCodeThe Python code to execute

Example: Temperature Logger

Here’s an example that logs temperature readings every minute:

import time
import json
from datetime import datetime
from random import uniform

# Configuration
log_file = "/var/log/temperature.log"
unit = "°C"

while True:
    # Simulate reading temperature
    temperature = round(uniform(18.0, 25.0), 2)
    timestamp = datetime.now().isoformat()

    # Create log entry
    log_entry = {
        "timestamp": timestamp,
        "temperature": temperature,
        "unit": unit
    }

    # Write to log file
    with open(log_file, "a") as f:
        f.write(json.dumps(log_entry) + "\n")

    print(f"Logged: {temperature}{unit} at {timestamp}")
    time.sleep(60)  # Wait 1 minute

Configuration for the Example

  • Python Packages: Add json if not using built-in, or any other packages like requests for API calls
  • Timer Configuration: Set up as a service that starts automatically
  • System Packages: Add any tools your script needs to call

Benefits

The Python Module provides several advantages over manual Nix expressions:

  • User-friendly: Write Python directly without Nix knowledge
  • Dependency management: Easy package selection via forms
  • Service integration: Automatic systemd service generation
  • Timer support: Built-in scheduling capabilities
  • Reusable: Share scripts across tags and device configurations

Migration from Custom Nix

If you have existing Python code in a Custom Nix Module using pkgs.writers.writePython3, you can easily migrate:

  1. Copy your Python code to the “Python Script” field
  2. Add your dependencies to the “Python Packages” list
  3. Configure the timer as needed
  4. Remove the old Nix expression

Advanced Usage

For complex scenarios, you can still combine the Python Module with other modules or use the Custom Nix Module for advanced systemd configurations.

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