iter2

This library provides implementation of rich-iterator concept, inspired by Rust's std::iter::Iterator, Java's Stream and more-itertools library.

The original purpose of this tool was to be used within a REPL (primarily IPython) environment for processing streaming data.

The goal of v2.x is to build upon the 7 years of experience gained from the production use of v1.x, to factor out redundant functionality, and to create a well-typed public API.

Usage

iter2 - the main API of this library, behaves like builtin iter but creates an instance of iter2.interfaces.Iterator2.

iter2.interfaces - module with library specific interfaces like Iterator2 and Iterable2.

iter2.algo - module with all algorithms and their curried versions.

iter2.op - module with useful operators like nth_item, pipe and mapping_items.

iter2.box and iter2.option - modules with types of "boxed values" Box2 and Option2.

import typing as tp

from iter2 import iter2


DATA: tp.Sequence[tp.Tuple[str, int | float]] = ...  # type: ignore

result: float | complex = (
    iter2(DATA)
    .filter_unpacked(lambda title, _: (
        title.startswith('Static typing')
    ))  # Iterator2[tp.Tuple[str, int | float]]
    .map_unpacked(lambda _, value: (
        -value,
    ))  # Iterator2[int | float]
    .filter_by_type(float)  # Iterator2[float]
    .apply_raw(
        iter2.algo.find_max_value
    )  # Option2[float]
    .value_or_else(lambda: 31337j)  # float | complex
)