python - return' outside function

Question

nums=[1,2,7,0]
target=9

for i in nums:
    for j in nums:
        if i+j==target and nums.index(i)<nums.index(j):
            return [nums.index(i),nums.index(j)]

File "<ipython-input-45-7bae4e6f6d77>", line 7
    return [nums.index(i),nums.index(j)]
SyntaxError: 'return' outside function

Answer 1

There is no function defined, but you use return. . . . .

Answer 2

Where to return?