pipef: Function Pipelines for Python

What is pipef?

pipef is a small, dependency-free library that chains callables with | instead of nesting them. One | operator covers two shapes: a reusable lazy function built once and called later, and an eager pipeline that pipes a value through immediately

pipef works as a double pun — pipe + function, but also pipe + forked, since each | in lazy mode forks a new immutable chain instead of mutating the old one

Linux, macOS, and Windows are all first-class citizens, and so is every Python from 3.8 up

Why Use pipef

See Comparison for the full survey against pipetools, toolz, sspipe, and others — in short:

• One operator, two shapes: the same | builds a reusable lazy function (pipef | f | g) or pipes a value eagerly (pipef(x) | f | g), instead of needing a different library for each

• Zero dependencies: nothing else installs alongside it

• Shared computation in eager mode: branching off an already-resolved eager chain reuses that prefix’s result instead of recomputing it per branch

• Multi-arg/kwarg seed: pipef(1, 2, c=3) | f seeds a chain with more than one value up front, which nothing surveyed in the comparison does

None of this is a reason to migrate off a library that’s already working for you — pipef is aimed at new code, or a project that wants both shapes without importing two libraries to get them

Key Features

• Lazy function factory: pipef | f | g builds a reusable, forkable function

• Eager value pipeline: pipef(x) | f | g applies each step immediately and hands back a result

• Immutable forking: piping further off any chain, lazy or eager, always returns a fresh pipef and leaves the original callable and unchanged

• Typed and dependency-free: ships py.typed, works on Python 3.8 through 3.14, and pulls in nothing else

Quick Start

Installation

pip install pipef

See Installing pipef for uv, Poetry, and Pipenv equivalents

Basic Usage

from pipef import pipef

fn = pipef | add_2 | mult_3
fn(2)
> 12

See Quick Start Guide for a slightly longer walkthrough, Advanced Usage for the full lazy/eager reference, or API Reference for the generated class docs