Python: List Comprehension: Leibniz Formula

Write the function leibniz that takes an integer k and returns sum of the firth kth terms in Leibniz series as follows. More information about the Leibniz series can be found here. $$ 1\,-\,{\frac {1}{3}}\,+\,{\frac {1}{5}}\,-\,{\frac {1}{7}}\,+\,{\frac {1}{9}}\,-\,\cdots \,=\,{\frac {\pi }{4}} $$

leibniz(1) -> 1
leibniz(3) -> 0.867

Test 1    

Test 2    

Test 3    

Test 4