The problem I see a lot of JS developers having when they start using Python is they try to do the "import the entire world" strategy of development that's common in JS, and there isn't good tooling for that because Python just doesn't have that culture. And that's because it's a bad idea--it's not a better idea in JS, it's just more part of the culture.

Pick one package source. Stick with it. And don't import every 0.0.x package from that package source either.

There are obviously reasons to use more than one package source, but those reasons are far rarer than a lot of inexperienced devs think they are. A major version number difference in one package isn't a good reason to complicate your build system unless there are features you genuinely need (not "would be nice to have", need).