What is the scope of l?

Question

Python

There is a code

def f(x,l=[]):
    for i in range(x):
        l.append(i)
    print(l)
f(3)
f(4)

Conclusion

[0, 1, 2]
[0, 1, 2, 0, 1, 2, 3]

I understand that l is not a static variable, because after the end of the function, the reference to the object is not deleted? Then l is enclosing? Does closure work here?