What are context managers in Python and how do I use the with statement?

What are context managers in Python and how do I use the with statement?

Context managers in Python are used to manage resources, ensuring they are properly acquired and released. The 'with' statement simplifies exception handling by encapsulating common preparation and cleanup tasks.

Can you give me an example of using a context manager with a file?

Sure! Here's a simple example:

with open('file.txt', 'r') as file:
    data = file.read()

In this example, the file is automatically closed after the block of code is executed.

What happens if an error occurs while using a context manager?

If an error occurs within the 'with' block, the context manager will still ensure that the resource is properly cleaned up, such as closing a file, even if an exception is raised.

Are there any built-in context managers in Python?

Yes, Python has several built-in context managers, such as open() for file handling, threading.Lock() for thread synchronization, and sqlite3.connect() for database connections.