# Async Cassandra Python Drivers: Alternatives and Comparisons

## Overview

The Python ecosystem offers several approaches to async Cassandra connectivity. This document provides a comparison of available options to help you make an informed decision based on your specific requirements.

## Available Solutions

### 1. async-python-cassandra-client (This Library)

**Project**: [https://github.com/axonops/async-python-cassandra-client](https://github.com/axonops/async-python-cassandra-client)
**Architecture**: Pure Python wrapper around the DataStax Python driver
**Language**: Python
**Dependencies**: cassandra-driver

**Key Characteristics:**
- Zero additional system dependencies
- Maintains 100% compatibility with existing DataStax driver code
- Easy migration path from sync to async code
- Stable, mature underlying driver
- No compilation or binary dependencies

**Technical Approach:**
- Uses thread pool for I/O (not native async)
- Bridges cassandra-driver futures to asyncio futures
- Maintains thread-based connection architecture

### 2. ScyllaPy

**Project**: [https://github.com/Intreecom/scyllapy](https://github.com/Intreecom/scyllapy)
**Architecture**: Rust-based driver with Python bindings
**Language**: Rust core with Python interface
**Dependencies**: Pre-compiled wheels or Rust toolchain for source builds

**Key Characteristics:**
- Native async implementation
- Built on Rust's tokio async runtime
- Includes query builder functionality
- Supports Cassandra, ScyllaDB, and AWS Keyspaces

**Technical Approach:**
- Implements Cassandra protocol directly in Rust
- Uses Rust's tokio async runtime for I/O
- PyO3 bindings expose Rust functionality to Python

### 3. Acsylla

**Project**: [https://github.com/acsylla/acsylla](https://github.com/acsylla/acsylla)
**Architecture**: C++ driver (cpp-driver) with Python bindings
**Language**: C++ core with Cython wrapper
**Dependencies**: Requires cassandra-cpp-driver

**Key Characteristics:**
- Based on DataStax C++ driver
- Supports shard-aware routing for ScyllaDB
- Comprehensive protocol support
- Available for Linux and macOS

**Technical Approach:**
- Uses libuv for async I/O
- Cython bindings for Python integration
- Leverages mature C++ driver codebase

### 4. DataStax AsyncioReactor (Experimental)

**Project**: Part of [python-driver](https://github.com/datastax/python-driver)
**Architecture**: Experimental asyncio integration in official driver
**Language**: Python
**Dependencies**: cassandra-driver

**Key Characteristics:**
- Integrated into official DataStax Python driver
- Pure Python implementation
- Marked as experimental/not production ready

**Technical Approach:**
- Replaces default reactor with asyncio-based implementation
- Still uses thread-based architecture internally

## Technical Comparison

### Architecture Comparison

| Aspect | async-python-cassandra-client | ScyllaPy | Acsylla | DataStax AsyncioReactor |
|--------|------------------------|----------|---------|-------------------------|
| I/O Model | Thread pool | Rust async (tokio) | C++ async (libuv) | Thread pool |
| Language Core | Python | Rust | C++ | Python |
| Binary Dependencies | None | Optional* | Required | None |
| Platform Support | All Python platforms | Windows/Linux/macOS | Linux/macOS | All Python platforms |
| Protocol Implementation | Wraps cassandra-driver | Direct in Rust | Wraps cpp-driver | Wraps cassandra-driver |

*Pre-built wheels available for common platforms

### Installation Complexity

**async-python-cassandra-client:**
```bash
pip install async-cassandra
# No additional system dependencies
```

**ScyllaPy:**
```bash
pip install scyllapy
# May require Rust toolchain for source builds
# Platform-specific wheels available
```

**Acsylla:**
```bash
# Requires cpp-driver installation first
apt-get install cassandra-cpp-driver  # Ubuntu/Debian
brew install cassandra-cpp-driver      # macOS
pip install acsylla
```

## Key Differences

### Async Implementation Approaches

**Thread Pool Based (async-python-cassandra-client, DataStax AsyncioReactor):**
- Wraps synchronous operations in thread pool executors
- Provides async/await syntax while maintaining thread-based I/O
- Compatible with all existing cassandra-driver features

**Native Async (ScyllaPy, Acsylla):**
- Implements protocol directly with async I/O primitives
- No thread pool overhead for I/O operations
- May have different feature sets from cassandra-driver

## Migration Considerations

### From DataStax Python Driver to async-python-cassandra-client

```python
# Before (sync)
from cassandra.cluster import Cluster
cluster = Cluster(['localhost'])
session = cluster.connect()
result = session.execute("SELECT * FROM users")

# After (async)
from async_cassandra import AsyncCluster
cluster = AsyncCluster(['localhost'])
session = await cluster.connect()
result = await session.execute("SELECT * FROM users")
```

**Migration effort: Minimal** - Add async/await keywords

### From async-python-cassandra-client to ScyllaPy/Acsylla

**Migration effort: Significant** - Different APIs, potential feature gaps

## Additional Considerations

### Ecosystem and Community

- **async-python-cassandra-client**: Leverages the mature DataStax driver ecosystem
- **ScyllaPy**: Growing community, active development
- **Acsylla**: Established project with ScyllaDB focus
- **DataStax AsyncioReactor**: Part of official driver but experimental status

### Documentation and Support

Each project maintains its own documentation. Refer to the project repositories linked above for:
- Installation guides
- API documentation
- Example code
- Issue tracking

### Compatibility Notes

- All libraries support basic Cassandra operations (queries, prepared statements, etc.)
- Feature parity varies for advanced functionality
- Check individual project documentation for specific feature support
- Protocol version support may differ between implementations
