$11.$ Implement the Function

Read the specification for the function and look at the test cases in the provided test script. With this information, complete the function, making sure to use an if$-$else statement. As there are only two possible types of e$-$mail addresses, it should be pretty straightforward to figure out how to do this.

The harder part is figuring out how to extract the name. This obviously involves string slicing, but you need to know where to slice. There are functions in the introcs module that can help you here.

When you have implemented the function, run the test script. If you have done it correctly, you should pass all tests.