How to make pip “dry-run”?

Question

For developing a script that runs pip install it would be usefull to have a --dry-run function.

I came across the --no-install op

Answer 1

Yes - pip should have a dry-run option, to indicate what would happen in a complex situation. It is dangerous when running pip install downgrades packages without asking you. We need some way to ask what would happen if we run pip install -r requirements.txt without laboriously searching thru all the requirements and comparing them to the currently installed ones.

It looks like setup.py used to have a dry-run. Folks are asking for it elsewhere.

Some progress in that direction can be found here:

• Dry Run for Python Pip | BackSlasher
• nvie/pip-tools: A set of tools to keep your pinned Python dependencies fresh.

Update: Activity continues on the official bug related to this: Add `pip install --dry-run` or similar, to get resolution result · Issue #53 · pypa/pip. It is blocked on the development of the dependency resolver, which is nearing completion