How does module importing (import) work in Python?

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The mechanism of importing modules and packages in Python is a fundamental part of working with code, determining how different files and libraries interact with each other. Understanding this process helps avoid typical visibility errors with files.

When you write an import statement, the interpreter starts searching for the target module through the list of paths stored in the sys.path variable. This list automatically includes the script's current working directory, the Python standard library, and all installed third-party packages.

When organizing a project structure, it is important to consider the following features of how imports work:

1. The local folder of your project is always at the beginning of the sys.path search list, allowing you to easily import your own files.
2. Historically, the __init__.py file was used to turn a regular folder into a package, and although in modern versions of Python this has become optional, it is still useful for package initialization.
3. To import files within the same package, use relative imports starting with a dot, for example: from .submodule import function.
4. Always try to avoid circular imports, where module A imports module B, and module B in turn tries to import module A, as this leads to an ImportError.

Proper file architecture and understanding the order in which sys.path operates ensure that your code will scale easily and run correctly from any directory.

How does module importing (import) work in Python?

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