What methods should a class implement to be used in a with statement for automatic resource management?

To use a class in a with statement in Python, it must implement the context manager methods:

• __enter__(self): called when entering the with block. Usually, resource initialization occurs here, and the method returns an object that will be accessible inside the block.
• __exit__(self, exc_type, exc_val, exc_tb): called when exiting the with block, even if an exception occurs inside the block. Resources are typically released here or cleanup is performed.

Example:

class FileManager:
    def __init__(self, filename, mode):
        self.filename = filename
        self.mode = mode
    
    def __enter__(self):
        self.file = open(self.filename, self.mode)
        return self.file
    
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.file.close()

with FileManager('test.txt', 'w') as f:
    f.write('Hello, world!')