YI JIANG2,913 Points
why it returns to none
Write a for loop that iterates over a range with a stop value of 10 (assume the start value is 0 and the step value is 1). The body of the for loop should append the current value to the provided list called my_list. To append a value to a list, use the syntax my_list.append(val).
my_list =  for val in range(10): print(my_list.append(val))
my_list = 
From the python docs:
You might have noticed that methods like insert, remove or sort that only modify the list have no return value printed – they return the default None. This is a design principle for all mutable data structures in Python.