After learning python which framework should I learn?

There are many popular and in-demand frameworks in the Python ecosystem, and the best one for you will depend on your interests and goals. Here are a few of the most widely used frameworks, along with some information about their strengths and common use cases:

1. Flask: Flask is a lightweight web framework that is easy to learn and use. It is commonly used for building small to medium-sized web applications and APIs. Flask has a large and active community, and there are many extensions available for adding additional functionality to your Flask applications.
2. Django: Django is a more comprehensive web framework that includes many built-in features for database access, authentication, and admin interfaces. It is commonly used for building larger, more complex web applications. Django has a large and well-established community, and there are many resources available for learning and using the framework.
3. FastAPI: FastAPI is a relatively new framework that has gained popularity for its performance and ease of use. It is designed for building APIs and microservices, and it includes features such as automatic documentation generation and data validation. FastAPI is built on top of the Starlette ASGI framework and the Pydantic data validation library.
4. PyTorch: PyTorch is a popular machine-learning framework that is widely used in research and industry. It provides a flexible and dynamic computational graph that allows for efficient and expressive deep-learning models. PyTorch is known for its ease of use and strong community support.
5. Scikit-learn: Scikit-learn is a popular machine-learning library that provides a wide range of algorithms and tools for data preprocessing, feature selection, and model training and evaluation. It is commonly used for building and deploying machine learning models in production.

In terms of demand, all of these frameworks and libraries are widely used and in high demand. Flask and Django are particularly popular for web development, while PyTorch and sci-kit-learn are commonly used in machine learning and data science. FastAPI is a newer framework, but it has already gained a strong following and is expected to continue to grow in popularity. Ultimately, the best framework for you will depend on your specific interests and goals.