Next time try using the </> symbol for code so that it keeps the indentation.
I think this is what you have?
def exponents(bases, powers):
new_lst = 
for base in bases:
for power in powers:
return new_lst.append(base ** power)
print(exponents([2, 3, 4], [1, 2, 3]))
.append() is a method which performs an action toward new_lst and doesn’t return anything.
I think you want to .append() the list after the powers in powers loop (where it is at now) but not return it. At the end after the list is created (after both for loops) then return the new_lst .
Here is an example of what you tried to do:
x = 
y = x.append(2)
>>> [1, 2]
See how y returns None? That is because .append() doesn’t return a value, but it still performed the action to append x. That’s kind of what you tried to do in your code.