Coding Environment

A Python code execution environment that runs arbitrary Python code and returns results. Perfect for testing code execution infrastructure and demonstrating environment usage patterns.

Quick Start

The simplest way to use the Coding environment is through the CodingEnv class. The client is async by default:

import asyncio
from coding_env import CodeAction, CodingEnv

async def main():
    # Create environment from Docker image
    client = await CodingEnv.from_docker_image("coding-env:latest")

    async with client:
        # Reset
        result = await client.reset()
        print(f"Reset complete: exit_code={result.observation.exit_code}")

        # Execute Python code
        code_samples = [
            "print('Hello, World!')",
            "x = 5 + 3\nprint(f'Result: {x}')",
            "import math\nprint(math.pi)"
        ]

        for code in code_samples:
            result = await client.step(CodeAction(code=code))
            print(f"Code: {code}")
            print(f"  → stdout: {result.observation.stdout.strip()}")
            print(f"  → exit_code: {result.observation.exit_code}")

asyncio.run(main())

For synchronous usage, use the .sync() wrapper:

from coding_env import CodeAction, CodingEnv

with CodingEnv(base_url="http://localhost:8000").sync() as client:
    result = client.reset()
    result = client.step(CodeAction(code="print('Hello!')"))
    print(result.observation.stdout)

The CodingEnv.from_docker_image() method handles:

• Starting the Docker container

• Waiting for the server to be ready

• Connecting to the environment

• Container cleanup when the context manager exits

Building the Docker Image

Before using the environment, you need to build the Docker image:

# From project root
docker build -t coding-env:latest -f envs/coding_env/server/Dockerfile .

Environment Details

Action

CodeAction: Contains a single field

• code (str) - The Python code to execute

Observation

CodeObservation: Contains the execution results

• stdout (str) - Standard output from code execution

• stderr (str) - Standard error from code execution

• exit_code (int) - Exit code (0 for success, non-zero for errors)

State

CodeState: Tracks execution state

• episode_id (str) - Unique identifier for the episode

• step_count (int) - Number of steps taken

• last_exit_code (int) - Exit code from the last execution

Advanced Usage

Connecting to an Existing Server

If you already have a Coding environment server running, you can connect directly:

from coding_env import CodeAction, CodingEnv

# Async usage
async with CodingEnv(base_url="http://localhost:8000") as client:
    result = await client.reset()
    result = await client.step(CodeAction(code="print('Hello!')"))

# Sync usage
with CodingEnv(base_url="http://localhost:8000").sync() as client:
    result = client.reset()
    result = client.step(CodeAction(code="print('Hello!')"))

Note: When connecting to an existing server, closing the client will NOT stop the server.

Development & Testing

Running Tests

Install the coding_env package with dev dependencies and run the tests from the repo root:

# Install coding_env with dev dependencies (includes smolagents and pytest)
uv pip install -e "envs/coding_env[dev]"

# Run unit tests (no Docker required)
uv run pytest tests/envs/test_python_codeact_reset.py tests/envs/test_python_codeact_rewards.py -v

# Run integration tests (requires Docker image to be built)
docker build -t coding-env:latest -f envs/coding_env/server/Dockerfile .
SKIP_DOCKER_TESTS=0 uv run pytest tests/envs/test_coding_env_integration.py -v

Running the Full Example

Run the complete example that demonstrates the full workflow:

python3 envs/coding_env/client/example_usage.py

This example shows:

• Creating an environment from a Docker image

• Resetting and executing code through the environment

• Automatic cleanup with close()

Project Structure

coding_env/
├── README.md              # This file
├── models.py              # Action, Observation, and State models
├── client/
│   ├── coding_env_client.py  # CodingEnv client implementation
│   └── example_usage.py      # Usage examples
└── server/
    ├── python_codeact_env.py  # Core environment logic
    ├── app.py                 # FastAPI application
    ├── transforms.py          # Observation transforms
    ├── Dockerfile             # Container image definition
    └── README.md              # Server-specific documentation