Question

After listening to lecture 9, I'm still confused about the merge and sort functions, particularly the lambda function (here's the code: http://codepad.org/cutcMoyR). On line 39, what is "float.__lt__" and how does it interact with the lambda function? Also, when it's changed to "gt" for "greater than" instead, it sorts in reverse order. How does that work? Thanks!

Answer 1

Oops, the url got messed up. It's http://codepad.org/cutcMoyR . Sorry about that.

Answer 2

When you define a function, you can give the last argument[s] default values. This allows the function to be called with fewer arguments than the prototype calls for. In this case, if you called sort( L ), it would work using the lambda function for comparison. sort() is acutally being passed the __lt__ method from the Float class to do the comparisons, overriding the lambda, so they don't interact. It's an either or thing.

Answer 3

Oh okay, that makes sense. Thanks!