The article explores the use of pytest's `raises()` function as a context manager to assert that a block of code raises a specific exception, using an example from the pytest documentation. It discusses the initially counterintuitive nature of using `excinfo` after exiting the `with` block, highlighting the differences between traditional file handling context managers and pytest's approach to handling exceptions. The author explains that while a file object becomes inaccessible after its context is closed, `excinfo` only becomes useful after the `with` block has concluded, once an exception has been raised and its details are filled in. The text delves into the underlying mechanics of `pytest.raises()`, detailing how the `__enter__` and `__exit__` methods work to manage the lifecycle of `excinfo`, transitioning it from an uninitialized state to being filled with exception details, thereby allowing assertions to be made outside the `with` block. This exploration underscores the elegance and clarity of this design pattern within pytest, offering a deeper understanding of how context managers can be leveraged in testing scenarios.