Delete old Python .venv and Rust target folders safely

Python: find real virtual environments

Names like env or venv aren't proof. A virtual environment always has a pyvenv.cfg file at its top:

find ~/Projects -name node_modules -prune -o -name pyvenv.cfg -print

Each result's folder is a venv (skipping node_modules keeps the search fast). Delete it with rm -rf; nothing inside is your code.

Recreate it

The project has	Command
uv.lock	uv sync
poetry.lock	poetry install
Pipfile	pipenv install
requirements.txt	python3 -m venv .venv && .venv/bin/pip install -r requirements.txt
pyproject.toml only	python3 -m venv .venv && .venv/bin/pip install -e .

Rust: target folders

Cargo's target/ holds every build profile and dependency you compiled, and grows with each toolchain update. In the project folder:

cargo clean

It's only a Rust build folder if there's a Cargo.toml next to it (Cargo also writes a CACHEDIR.TAG file inside). A target folder next to a pom.xml is Maven's build output instead: mvn clean or ./mvnw clean.

The shared caches

• pip: pip cache purge (pip cache dir shows where it is).
• uv: uv cache prune removes only unused entries; uv cache clean empties it.
• Cargo: downloaded crates live in ~/.cargo/registry and are shared by every Rust project.