Context managers in Python are used to manage resources efficiently. Here’s an example:

with open('example.txt', 'w') as file:
    file.write('Hello, world!')

You can also create custom context managers using classes or the contextlib module:

from contextlib import contextmanager

@contextmanager
def custom_context():
    print('Entering context')
    yield
    print('Exiting context')

with custom_context():
    print('Inside context')

Context managers ensure that resources are properly cleaned up, making your code more reliable and maintainable.

python -c "with open('example.txt', 'w') as file: file.write('Hello, world!')"