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I have a question about imports. The question might seem a bit contrived, but its purpose is to explore the limitations of using absolute imports for all imports in a package. PEP8 highly discourages relative imports (edit: and the Google Python Style Guide says never to use them).
Say you are given two large-ish packages that both have the same name and that both use absolute imports in accordance with PEP8:
/pkg1
mod1.py (contains an absolute import: 'import pkg1.mod2')
mod2.py
...
/pkg1
mod1.py (contains an absolute import: 'import pkg1.mod3')
mod3.py
...
Also say you are working on a Python project in which you'd like to use both packages. This could come up, say, if you want to use two versions of the same package in a project.
Is there a way to incorporate both packages into your project hierarchy so that you can freely use modules from both packages throughout your project?
For the solution it's acceptable to do things like use import aliases and modify sys.path temporarily. But it's not okay to change the contents of either package directory.
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To import two classes with the same name, use the as keyword to rename one or both of the imports, e.g. import {Employee as Employee2} from './another-file-2. js'; . The as keyword allows us to change the identifying name of the import.
Polymorphism works in two cases one in same class where function with same name and different number of arguments(function overloading) the other is in inheritance when both function names are same in base class and derived class with same arguments and same return type( function overriding ).
easy_install allows simultaneous installation of different versions of the same project into a single environment shared by multiple programs which must require the appropriate version of the project at run time (using pkg_resources ).
What happens if a module is imported twice? The module is only loaded the first time the import statement is executed and there is no performance loss by importing it again. You can examine sys. modules to find out which modules have already been loaded.
The short answer is no, Python doesn't accept two packages with the same name. (There are things called "namespace packages" that let a single package be implemented over multiple directories but they require the packages involved to be set up to cooperate with each other).
The way PEP 8 discourages explicit relative imports is one of its more questionable pieces of advice, precisely because it makes it harder to rename a package to avoid naming conflicts. If the two packages used relative imports, you could just rename one of them or nest it inside another package and be done with it.
import aliases won't help you here, because it is the name that ends up in sys.modules that matters, and that uses the name of the module as imported, rather than the name that ends up being bound in the importing module.
If you wanted to get really exotic, you could write your own importer (see PEP 302 and the 3.x importlib documentation). If you decide to go that far, you can do pretty much anything you want.
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