chumicro-compat 0.1.21

Cross-runtime compatibility polyfills for CircuitPython, MicroPython, and CPython — functools.partial and more.

chumicro-compat

Standard library features that CircuitPython and MicroPython are missing.

Import from chumicro_compat instead of the stdlib and your code works everywhere. On CPython it re-exports the real C implementations (zero overhead); on microcontrollers it provides lightweight pure-Python versions.

Part of the ChuMicro family — small, focused Python libraries for microcontrollers and laptops. See all libraries.

Installation

CircuitPython (circup)

circup is CircuitPython's package manager — it uses bundles to find third-party packages. Register the ChuMicro bundle once, then install by name:

circup bundle-add ChuMicro/ChuMicro-Bundle
circup install chumicro-compat

MicroPython (mip)

mpremote mip install github:ChuMicro/ChuMicro-Bundle/chumicro_compat

CPython (pip)

pip install chumicro-compat

Experimental (pre-release) versions and channel switching

Pre-release builds are published automatically when a library version is bumped. Do not register both bundles simultaneously — circup may pick either version for a given package.

# CircuitPython — switch to experimental
circup bundle-remove ChuMicro/ChuMicro-Bundle              # skip if never added
circup bundle-add ChuMicro/ChuMicro-Bundle-Experimental
circup install chumicro-compat

# MicroPython
mpremote mip install github:ChuMicro/ChuMicro-Bundle-Experimental/chumicro_compat

# CPython
pip install chumicro-compat-experimental

Quick example

from chumicro_compat.functools import partial

def set_led(pin: int, brightness: int) -> None:
    """Set an LED pin to a brightness level."""
    print(f"pin {pin} → {brightness}%")

# Freeze the pin, vary the brightness later.
set_status_led = partial(set_led, 13)
set_status_led(50)   # pin 13 → 50%
set_status_led(100)  # pin 13 → 100%

What's included

functools

Symbol	Description
partial(func, *args, **keywords)	Freeze positional and keyword arguments to a callable
partial.func	The original wrapped callable
partial.args	Frozen positional arguments (tuple)
partial.keywords	Frozen keyword arguments (dict)

Platform support

Runtime	What happens
CPython	Uses the built-in functools.partial directly — zero overhead
MicroPython	Lightweight pure-Python replacement
CircuitPython	Lightweight pure-Python replacement

The public API (.func, .args, .keywords, __call__, __repr__) is identical across all runtimes.

Examples

Example	What it shows
partial_basic.py	Freeze one argument to a function
partial_keyword_override.py	Freeze keyword args, override at call time
partial_callback.py	Wire a callback with frozen context (embedded pattern)

Docs

📖 Stable docs · Experimental docs

Find this library

• PyPI: chumicro-compat
• Bundle: ChuMicro-Bundle (CircuitPython & MicroPython)
• Experimental bundle: ChuMicro-Bundle-Experimental
• Source: libraries/compat