Python Under 5 Minutes: Reduce Function 

The reduce function is a built in function that will take two values, one of them being the result of the addition (we are starting at 0 except for that last example with an initializer) and the other value being the next number to add (each value in the list one at a time) and we will pass both of those values into the add function, it will call the add function for each number in the list. So what the reduce function is actually doing would look something like this: add(0,10) -> add(10,1) -> add(11, 2) -> add(13, 3) -> add(16, 4) -> add (20, 5) -> return 25 (because 5 is the last value). With each time the add function is called, the a variable will hold the current sum value up until that point, when there is nothing left to add, we return the final value. Hopefully that helps clear up any confusion with this, let me know if that still doesn't make sense. Thanks for watching!

@@LegionScript Thank you for taking the time to write out such a detailed response. I understood how it got to 25, but didn’t understand the fundamentals. Your explanation is very helpful for a Python newb.