Cleanup and project

Questions 1 to 5 of 8

1. 1. Put these steps in the order Python runs them when a with Res("A") as a, Res("B") as b: block ends normally. B was opened after A.

   Use the arrows to put the steps in order.

   1. 1.Python calls __exit__ on a↑↓
   2. 2.Execution moves on to the line after the with statement↑↓
   3. 3.Python calls __exit__ on b, the resource opened last↑↓
   4. 4.The statements inside the with block run↑↓
2. 2. A class has a close method but no __enter__ or __exit__. What does Python report for this code? ``python class Plain: def close(self): print("closed") with Plain() as p: print("working") ``

   TypeError: 'Plain' object does not support the context manager protocol (missed __exit__ method)It prints working, then closed, because Python calls close() automaticallyIt prints working, because p is only a name and needs no methodsAttributeError: 'Plain' object has no attribute 'close'
3. 3. What does this program print? ``python class Res: def __init__(self, name): self.name = name def __enter__(self): return self def __exit__(self, exc_type, exc, tb): print("close", self.name) try: with Res("A") as a, Res("B") as b: raise RuntimeError("oops") except RuntimeError as err: print("caught", err) ``

   close A, close B, caught oopscaught oops, close B, close Aclose B, close A, caught oopsclose B, caught oops, close A
4. 4. In with Flaky(): raise RuntimeError("body failed"), the __exit__ method of Flaky also raises RuntimeError("close failed"). What does the except block see? ``python class Flaky: def __enter__(self): return self def __exit__(self, exc_type, exc, tb): raise RuntimeError("close failed") try: with Flaky(): raise RuntimeError("body failed") except RuntimeError as err: print("caught:", err) print("context:", repr(err.__context__)) ``

   Only close failed, because __exit__ runs last and the body error is lostBoth messages joined into one message, body failed close failedThe program stops with a traceback before the except block runsclose failed as the main error, with RuntimeError('body failed') attached as __context__
5. 5. Put these steps in the order that Store.sell_all uses for a whole order with several lines.

   Use the arrows to put the steps in order.

   1. 1.If every line passed, call remove_stock for each line↑↓
   2. 2.Check every line of the order against the stock, and raise if any line cannot be filled↑↓
   3. 3.The method returns, and every line has been sold↑↓