Daniel Arbuckle's Mastering Python

Accessing code from other modules

We'll start off this section by understanding the difference between absolute and relative imports, then move on to writing those, and finally, we'll look at cyclic dependencies.

When we are importing one of the package's modules from outside the package, there's only one sensible way that it could work-we tell Python which package and module we want, and it either finds and imports it or raises an exception if it can't. Simple!

import packagename.modulename  

When we're already inside a package, the situation is more ambiguous because import name could just as easily mean "look for name within this package" or "look for name in the Python search path." Python breaks this ambiguity by defining import name ...