Functions that use yield are known as "generators". Before Python 3.3, generators cannot return values. Similarly, functions that use return cannot use yield. Doing so will cause a SyntaxError.

Either upgrade your version of Python to a version >= 3.3, or don't use both return and yield in a function.

Noncompliant Code Example

def adder(n):
     num = 0
     while num < n:
         yield num
         num += 1
     return num  #Noncompliant