Automation & Scripting Flashcards

Which Python module provides the `run()` function for executing shell commands and capturing output?

Answer: subprocess

`subprocess.run()` executes a command, waits for it to complete, and returns a CompletedProcess instance with stdout/stderr.

In a Python automation script, what does `subprocess.run(['ls', '-la'], capture_output=True, text=True)` return?

Answer: A CompletedProcess object with stdout and stderr as strings

`capture_output=True` and `text=True` make `run()` return a CompletedProcess whose `.stdout` and `.stderr` are decoded strings.

Which `schedule` library method runs all pending scheduled jobs?

Answer: schedule.run_pending()

`schedule.run_pending()` checks all registered jobs and runs any whose next run time has passed.

What is the purpose of the `watchdog` library in Python automation?

Answer: Monitor filesystem events and trigger callbacks

`watchdog` monitors file system changes (create, modify, delete) and dispatches events to handler classes.

Which context manager ensures a file is properly closed even if an exception occurs during reading?

Answer: `with open(filename) as f:`

The `with` statement calls `__exit__` on the file object, closing it automatically even if an exception is raised inside the block.

In Python's `argparse`, what does `add_argument('--verbose', action='store_true')` do?

Answer: Sets the attribute to True when the flag is present, False otherwise

`action='store_true'` sets the destination attribute to `True` when the flag appears and `False` when it is absent.

Which Python function sends an HTTP GET request when using the `requests` library?

Answer: requests.get()

`requests.get(url)` sends an HTTP GET request and returns a `Response` object with `.status_code`, `.text`, and `.json()` method.