Handle files created on the fly.

[iCHAIT]

Hi, thanks for this great tutorial, I wanted to ask a question -

My python script which I have packed writes to a file, this file is not shipped with the package so in essence it is created on the fly for the user (that is when he runs the package.).

Now I want to know, how do I handle such a file?

Currently I have not specified it in my setup.py because it has not been shipped with the package, do I need to define it in setup.py and maybe ship it is an empty file?

[storborg]

This isn't really something that Python has strong conventions for, but personally I think:

• It is generally harmful to write to any files inside the installed package itself: sometimes, it will be installed as a zip file (although this can be disabled in setup.py), and it is often not user-writeable.
• If it's a temporary file, use the tempfile module.
• If it's user-specific, use a dotfile (e.g. /home/someuser/.mypackagename). This is a location that's both un-surprising to the user and is very likely to succeed without permissions errors. You should get the path to the home directory with os.path.expanduser("~") so that it's cross-platform. If you need multiple files, make .mypackagename a directory instead, and put files inside it.
• If it's system-wide, you probably have to at least prompt the user before writing, since there isn't a consistent system-wide path that the user is likely to have write permissions for. You may be able to default to something like /usr/local/share/mypackagename on POSIX systems.

Also, those files should not be defined in setup.py at all: your setup.py should only reference read-only files which are included with the package.

[iCHAIT]

Thanks a lot :+1:

FIxed using os.path.expanduser("~")