Python's execution model
In this paragraph, I would like to introduce you to a few very important concepts, such as scope, names, and namespaces. You can read all about Python's execution model in the official Language reference, of course, but I would argue that it is quite technical and abstract, so let me give you a less formal explanation first.
Names and namespaces
Say you are looking for a module, so you go to the library and ask someone for the module you want to fetch. They tell you something like "second floor, section X, row three". So you go up the stairs, look for section X, and so on.
It would be very different to enter a library where all the books are piled together in random order in one big room. No floors, no sections, no rows, ...
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