Can you explain advanced context manager examples in Python?

Can you explain advanced context manager examples in Python?

Sure! Advanced context managers in Python can be created using the contextlib module. For instance, you can use contextlib.contextmanager to create a context manager that handles resources more flexibly.

Can you give me a specific example of using contextlib?

Absolutely! Here's a simple example: you can create a context manager that opens a file and ensures it gets closed properly, even if an error occurs.

How does the __enter__ and __exit__ methods work in a custom context manager?

The __enter__ method is executed when the execution flow enters the context of the manager, and it can return a value to be used within the context. The __exit__ method is called when the execution flow leaves the context, allowing you to handle cleanup.

Can you show me a code snippet for a custom context manager?

Sure! Here's a simple custom context manager that measures the execution time of a block of code:

import time

class Timer:
    def __enter__(self):
        self.start = time.time()
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        self.end = time.time()
        print(f"Execution time: {self.end - self.start} seconds")

with Timer():
    # Your code here