linfo2335-programming-paradigms/project-3/regex/code/code2073.py

def approx_pi(i):        
    if i == 0:
        print(4)
    else:
        if i == 1:
            print(2.666666666)
        else:
            if i == 2:
                print(3.46666666)
            else:
                if i == 3:
                    print(2.8952381)
                else:
                    pi = 0
                    for j in range(i+1) :
                        pi += (((-1)**i) / ((2*i)+1))
                    return(4*pi)