Is there a difference between flit install and pip install?

Question

flit provides an install option. I just wonder what is the difference between flit install --symlink and pip install --editable ., or more generally, flit install and pip install? Unfortunately the documentation is currently not clear about this at all:

Install the package on your system.

By default, the package is installed to the same Python environment that Flit itself is installed in; use --python or FLIT_INSTALL_PYTHON to override this.

If you don’t have permission to modify the environment (e.g. the system Python on Linux), Flit may do a user install instead. Use the --user or --env flags to force this one way or the other, rather than letting Flit guess.

They both seem to be doing the same thing, when should I use pip and when flit?

Answer 1

With a normal install, they're both doing the same thing - whichever tool you call, Flit builds a wheel and pip installs it. There was more difference in the past (like the auto user installation mentioned in the docs you quoted), but now it's almost exactly the same.

Flit's --symlink option achieves a similar result to --editable but works in a different way (which I happen to prefer :-). The --pth-file option should be identical to --editable.