aiostream

Introducing aiostream

aiostream is a powerful Python library designed to facilitate asynchronous iteration by offering generator-based operators. It is a versatile tool that allows developers to build asynchronous data processing pipelines akin to the well-known itertools module, albeit with some differences tailored for asynchronous programming.

Key Features

aiostream enriches asynchronous iterables with its stream interface, providing numerous enhancements such as:

• Operator Pipelining: You can pass data through multiple stream operations using the pipe symbol |. This makes it easy to chain operations in a clean and readable manner.
• Repeatability: Each iteration of a stream creates a different iterator, allowing for repeated processing without duplication concerns.
• Safe Iteration Context: By utilizing async with and the stream method, aiostream ensures resource management is safe and efficient.
• Simplified Execution: Retrieve the last element from a stream using await, simplifying asynchronous operations.
• Slicing and Indexing: Access specific parts of streams using convenient square brackets [].
• Concatenation: Combine streams effortlessly using the addition symbol +.

Stream Operators

aiostream offers a variety of stream operators, categorized into seven distinct groups:

• Creation: Functions like iterate, preserve, and just help initiate streams in various ways, such as creating a stream of repeated elements or generating elements on the fly with call.

• Transformation: Transform data within a stream using operators like map, enumerate, and cycle.

• Selection: Select specific elements with operators such as take, filter, and until.

• Combination: Merge multiple streams into one using zip, merge, or chain functionalities.

• Aggregation: Aggregate data with tools like accumulate and reduce.

• Advanced: Advanced data manipulation with concat, flatten, and mapping techniques like concatmap.

• Timing: Time-related operations are handled with spaceout, timeout, and delay.

• Miscellaneous: Additional functionalities such as action and print for various purposes.

Demonstration

A simple demonstration of aiostream in action:

import asyncio
from aiostream import stream, pipe

async def main():
    # Create a counting stream with a 0.2 seconds interval
    xs = stream.count(interval=0.2)
    # Operators can be piped using '|'
    ys = xs | pipe.map(lambda x: x**2)
    # Streams can be sliced
    zs = ys[1:10:2]
    # Use a stream context for proper resource management
    async with zs.stream() as streamer:
        # Asynchronous iteration
        async for z in streamer:
            # Print 1, 9, 25, 49 and 81
            print('->', z)
    # Streams can be awaited and return the last value
    print('9² = ', await zs)
    # Streams can run several times
    print('9² = ', await zs)
    # Streams can be concatenated
    one_two_three = stream.just(1) + stream.range(2, 4)
    # Print [1, 2, 3]
    print(await stream.list(one_two_three))

# Run main coroutine
loop = asyncio.get_event_loop()
loop.run_until_complete(main())
loop.close()

Installation

Installing aiostream is simple and can be done from PyPI, allowing easy integration into Python projects as the aiostream package.

Contact

Vincent Michel, the maintainer, can be reached at [email protected] for further inquiries or contributions.

For more examples and a thorough exploration of aiostream's capabilities, the official aiostream documentation provides extensive resources and guidance.