sqrt.py

def sqrt(x, b=2):
    if x < 0:
        x = abs(x)
        img = True
    else:
        img = False

    i = 0
    r = x
    lr = 0

    while True:
        i += 1
        lr = r
        r = (((b - 1) * r) + x / (r ** (b - 1))) / b
        if lr == r:
            break

    if img:
        r = r * 1j
    return r