You and the parent are mistaken about the cause of Python’s performance problems. Python isn’t slow because it’s readable—it could be quite a lot faster without compromising readability. Python is slow because it exposes the entire CPython interpreter as the C-extension API, which means they can’t change much about the interpreter without breaking compatibility with some extensions (and they are unwilling to do so). Since performance is so bad, the community leans hard on C-extensions, which worsens the problem.

I suspect one of the reasons packaging is so bad is because for each node on the dependency tree, you need to download and execute setup.py in order to discover the node’s direct dependencies, and to get the transitive dependencies you must download and execute the direct dependencies’ setup.py filles. Since these files aren’t idempotent, we can’t reliably cache the results (these scripts could return different sets of dependencies based on the environment or even the current time or anything else). This at least seems to be the reason all reproducible package managers are slow (by which I mean 30+ minutes to resolve dependency versions for a small non-toy project even if the resolved dependencies at their property versions are already cache to disk).