conda-lock vs pip-tools

conda-lock is a lightweight library for producing reproducible lockfiles for conda environments. It solves dependencies separately for each target platform, allowing installations from generated lockfiles to avoid running the conda solver. Inputs can come from environment.yml, conda-build meta.yaml, or pyproject.toml dependency specifications. Its default unified lockfile covers multiple platforms and can be rendered into other lockfile formats. Documented target examples include Linux, macOS, Windows, and additional Linux architectures. The project describes use alongside conda, mamba, pip, Docker, and pixi, and provides installation routes through pip, conda, and mamba; pipx or condax are recommended for isolated installation. Mixed conda-and-pip locking is experimental. Channel access supports token or basic authentication, with environment-variable substitution for credentials. The unified lockfile can omit raw credential-bearing channel URLs when it matches credential portions to environment variables, although rendered explicit lockfiles may contain substituted variables. Private pip repository support is limited to legacy PyPI repositories using basic authentication. The software is MIT-licensed and free.

pip-tools is a free set of command-line tools for keeping pinned pip-based packages current and making builds more predictable. Its two core commands are pip-compile and pip-sync. pip-compile generates requirements.txt files from pyproject.toml, setup.cfg, setup.py, or requirements.in, and can handle project and optional dependencies in pyproject.toml. It can also generate hashes for pip hash-checking mode. pip-sync installs, upgrades, or removes packages to make a virtual environment match a compiled requirements.txt file. Defaults can be configured in .pip-tools.toml or pyproject.toml, and pip-compile can be used as a pre-commit hook. The tools support Linux, macOS, and Windows, and the package requires Python 3.9 or later. Compilation results may differ across operating systems, Python versions, and implementations, so the project advises compiling separately for each target environment. The default backtracking resolver is described as more robust but generally slower; the legacy resolver is deprecated. pip-tools is distributed under the BSD License.