How to install a config file if it does not exist, not overwrite it during upgrade and not delete it during uninstall?

Question

As outlined in the documentation I've added the data_files variable to setup.py to install a config file when the package is installed:

setup(...,
      data_files=[('/greg/home/package', ['config']),]
     )

How to install the config file if one does not exist, but not:

• uninstall it or
• overwrite it during install --upgrade?

For example, when I try to uninstall the package, the config file is included in the list of files to be deleted.

$ pip uninstall package
Uninstalling package-0.1.0:
  ...
  /home/greg/package/config
Proceed (y/n)? 

How to only install config file if one does not exist and use the user's version otherwise?

Answer 1

Generally, most packages handle config files like this by only providing an example config, and requiring the user to change the filename or move it to a different location so that it won't get overwritten or deleted.

Another thing that some packages will do is provide a command line script to help generate the config (e.g. Sphinx, Django) in a user specified location, instead of packaging a config with the project.