Can use capwords() function...
https://docs.python.org/3/library/string.html#helper-functions

Can also use join() function...
https://docs.python.org/3/library/stdtypes.html#string-methods

The array is passed into the reducer function by reference. It is okay to mutate the array inside the reducer function just like it's okay to mutate any other object passed in by reference. While this array is mutated, the original array "plan" is untouched. This is fine, too. The reducer function, however, can have up to four parameters, of which the fourth parameter is a reference to the source array. Mutating the source array in the reducer function would be the problematic case. This is akin to modifying an array while iterating through it.

The empty array, the value of the second parameter of the reduce method. The second parameter is optional. When it is not used, the accumulator of the reducer function is initialized with the first element of the array.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce

First time using Array.map method...
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map

Could have used the String.repeat method to build the bottom floor.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat