Python Packaging for Developers in a Hurry

Thanks a lot, that&#x27;s a great intro to many useful tools. I have 2 questions.<p>Managing dependencies<p>&quot;If you’re developing a library, use nothing. Let your users decide, and give them as much flexibility as possible to maximize compatibility (don’t pin, unless to exclude some known-to-fail version ranges).&quot; What does this &quot;nothing&quot; contain? :-) A `requirements.txt`? Do you test the library with various versions of that dependency (e.g. with tox)?

Docker<p>&quot;Using a virtual environment inside a Docker container is perhaps over-the-top, but it provides extra isolation from the base image’s own Python dependencies, and the entire &#x2F;venv folder can be copied over between stages if you need.&quot;<p>Do you have some use cases in mind when this can be handy?