A property which is exposed by the article's solution too: >>> x = (lambda: (yield 1))() # generator with one step >>> y = tuple(x)[0] >>> y 1 >

A property which is exposed by the article's solution too: >>> x = (lambda: (yield 1))() # generator with one step >>> y = tuple(x)[0] >>> y 1 >>> list(x) # exhausted [] >>> x = (lambda: (yield 1))() >>> y, = x >>> y 1 >>> list(x) # exhausted, too! [] Because that's just what you inevitably need to do to fetch a value from a generator. There is no peeking action or some such.