There are 365k projects in the "official" package index. While not all of these are important, it's a tip-off to the magnitude of the problem. The habit of blowing past a problem by grabbing a random library and moving on to the next problem leaves us with a mess of dependencies. And many of those were either written by amateurs like us, not maintained, etc.
Maybe other languages have fewer libraries, or maybe the habit of grabbing libraries at random evolved concurrently with the rise of Python.
My team has a rule that we don't let a project get past a certain stage without proving that it can be installed and run on a clean machine and archiving all of the necessary repo's with the project. It's easily forgotten that testing your installer is part of testing your program.
Maybe other languages have fewer libraries, or maybe the habit of grabbing libraries at random evolved concurrently with the rise of Python.
My team has a rule that we don't let a project get past a certain stage without proving that it can be installed and run on a clean machine and archiving all of the necessary repo's with the project. It's easily forgotten that testing your installer is part of testing your program.