Why is the context manager 'with' used when working with files? Where else is it applied?

The with statement in Python is used for ensuring the proper opening and closing of resources, such as files. When working with files, it automatically closes the file after exiting the block, even if an exception occurs.

Example:

with open('file.txt', 'r') as f:
    data = f.read()
# file is automatically closed here

Besides working with files, with is used to manage any resources that require explicit release:

• Network connections
• Locks (threading.Lock)
• Database transactions
• Temporary state changes (e.g., temporary configuration changes)

For this, the object must implement the __enter__ and __exit__ methods, which manage entering and exiting the context.