How do I use context managers in Python?

How do I use context managers in Python?

Context managers in Python are used to manage resources, like file streams. You can use the with statement to ensure proper acquisition and release of resources.

Can you give me an example of a context manager?

Sure! Here's a simple example:

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

This automatically closes the file after the block is executed.

What happens if an error occurs inside the with block?

If an error occurs, the context manager will still ensure that the resource is properly released. In the file example, the file will be closed even if an exception is raised.

Are there any built-in context managers?

Yes, Python has several built-in context managers, such as open(), threading.Lock(), and sqlite3.connect(). You can also create your own using the contextlib module.