# House Recite the nursery rhyme 'This is the House that Jack Built'. > [The] process of placing a phrase of clause within another phrase of > clause is called embedding. It is through the processes of recursion > and embedding that we are able to take a finite number of forms (words > and phrases) and construct an infinite number of expressions. > Furthermore, embedding also allows us to construct an infinitely long > structure, in theory anyway. - [papyr.com](http://papyr.com/hypertextbooks/grammar/ph_noun.htm) The nursery rhyme reads as follows: ```text This is the house that Jack built. This is the malt that lay in the house that Jack built. This is the rat that ate the malt that lay in the house that Jack built. This is the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the cow with the crumpled horn that tossed the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the maiden all forlorn that milked the cow with the crumpled horn that tossed the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the man all tattered and torn that kissed the maiden all forlorn that milked the cow with the crumpled horn that tossed the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the priest all shaven and shorn that married the man all tattered and torn that kissed the maiden all forlorn that milked the cow with the crumpled horn that tossed the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the rooster that crowed in the morn that woke the priest all shaven and shorn that married the man all tattered and torn that kissed the maiden all forlorn that milked the cow with the crumpled horn that tossed the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the farmer sowing his corn that kept the rooster that crowed in the morn that woke the priest all shaven and shorn that married the man all tattered and torn that kissed the maiden all forlorn that milked the cow with the crumpled horn that tossed the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. This is the horse and the hound and the horn that belonged to the farmer sowing his corn that kept the rooster that crowed in the morn that woke the priest all shaven and shorn that married the man all tattered and torn that kissed the maiden all forlorn that milked the cow with the crumpled horn that tossed the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built. ``` ## Exception messages Sometimes it is necessary to raise an exception. When you do this, you should include a meaningful error message to indicate what the source of the error is. This makes your code more readable and helps significantly with debugging. Not every exercise will require you to raise an exception, but for those that do, the tests will only pass if you include a message. To raise a message with an exception, just write it as an argument to the exception type. For example, instead of `raise Exception`, you shold write: ```python raise Exception("Meaningful message indicating the source of the error") ``` ## Submitting Exercises Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/` directory. For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit /python/bob/bob.py`. For more detailed information about running tests, code style and linting, please see the [help page](http://exercism.io/languages/python). ## Source British nursery rhyme [http://en.wikipedia.org/wiki/This_Is_The_House_That_Jack_Built](http://en.wikipedia.org/wiki/This_Is_The_House_That_Jack_Built) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.