We can solve this prompt using a for loop as follows:

def add(num):# if num is an integer thenif type(num) == int:# create sum variable and assign it to 0sum = 0# using a for loop, loop over integers 0 to numfor x in range(num+1):# update sum valuesum += x# return sumreturn sum# if num is not an integer then return 0else:

return 0

## Let’s dissect the code below.

We first check if the value passed in, **num**, is an integer using the **type **function.

`if type(num) == int:`

If the type is an integer, we create a **sum **variable and assign it the value 0.

`sum = 0`

We then loop over the integers starting from 0 through the integer passed in to our function using a for loop and the **range **function. Remember that the range function creates a **range object**, which is an iterable object, that starts at 0 (if we don’t specify a start value), and goes to the integer less than the stop value (since the stop value is exclusive). That is why we need to add 1 to the stop value (**num+1**), since we want to add up all the integers from 0 up to and including that number, **num**.

`range`

(start, stop[, step])

The range function will create a range object, which is an iterable object, and thus we can use a for loop to loop through it. As we are looping through this iterable object, we are adding each number, or **x**, to the **sum **variable.

`for x in range(num+1):`

** **sum += x

Then after the for loop iterations are complete, the function returns the sum.

`return sum`

Lastly, if the number passed in is not an integer, we return 0.

`else:`

return 0