Functions - General Questions

What is the output of the following code?

def fact(n):
    return 1 if n <= 1 else n * fact(n - 1)
print(fact(5))

Which parameter kind must be passed by keyword in def f(a, *, b):?

What is the output of the following code?

def f():
    pass
print(f())

What is a docstring?

What is the output of the following code?

def f(**kw):
    return sorted(kw)
print(f(b=2, a=1))