Backslashes with lamda not used in example?

within the hands-on with pandas lesson (9/1 2) there is a block of example code for a lambda function containing no backslash lines and we are told we do not exactly need them. However you cannot get the answer correct without then adding them? Any guidance as to what is really needed and whether backslashes are required?

The example is wrong. You need a backslash in the lambda function b/c it (the function’s logic & physical line) continues on the next physical line w/the control flow. Or, in other words: two or more physical lines can be joined as logical lines with a backslash.

See the documentation: