Скачать или смотреть Why You Can Only Import Your Classes Using from module import class and Not import module

Discover why you need to use 'from module import class' instead of 'import module' to import classes in Python, and understand how Python handles module imports.
---
Disclaimer/Disclosure: Some of the content was synthetically produced using various Generative AI (artificial intelligence) tools; so, there may be inaccuracies or misleading information present in the video. Please consider this before relying on the content to make any decisions or take any actions etc. If you still have any concerns, please feel free to write them in a comment. Thank you.
---
Why You Can Only Import Your Classes Using from module import class and Not import module

When programming in Python, you may have encountered situations where you can only import your classes using from module import class rather than just import module. This specificity in importing has to do with how Python handles and organizes its modules and objects.

The Difference Between import module and from module import class

import module: This statement imports the entire module. When you use this statement, you have to qualify the usage of any classes or functions from the module with the module's name. For instance, if you import a module named mymodule, you must use mymodule.MyClass to access MyClass.

[[See Video to Reveal this Text or Code Snippet]]

This makes sense when you want to import all the contents of a module but want to minimize the risk of name clashes in your code.

from module import class: This statement imports only the specified class (or function) from the module. It allows you to directly use MyClass without needing to prefix it with the module name.

[[See Video to Reveal this Text or Code Snippet]]

This can make your code cleaner and more readable, especially if you only need one or two classes from the module.

The Granularity of Python's Import System

Python modules are generally structured to contain multiple classes and functions. By importing a specific class or function, the Python interpreter saves memory and reduces namespace pollution by not loading unnecessary classes or functions into your working memory. This granularity allows more controlled and efficient coding.

Also, by using from module import class, the interpreter is able to rapidly locate and load the class, since it does not need to traverse through the entire module to locate the needed functionality.

Preventing Circular Imports

Another important aspect of why specific imports are encouraged is to prevent circular import issues. Circular imports can occur when two or more modules depend on each other. By importing only the specific class or function, you reduce the chances of running into these problems.

[[See Video to Reveal this Text or Code Snippet]]

This code above would cause a circular import error. By being specific about what you import, you can often avoid such issues.

Conclusion

Understanding the difference between import module and from module import class is crucial for optimizing your Python code. The latter allows for more precise, readable, and efficient code by only importing the necessary components. Additionally, it helps in managing the namespace more effectively and reduces the risk of circular import errors.

When deciding how to structure your imports, consider the needs of your project, and choose the method that makes your code more efficient and easier to read.