Here's an Editor box, try running the code supplied (tests if the point x,y lies in the mandelbrot set):
def mandel(x, y, maxiter = 20): c = complex(x, y) z = complex(0, 0) for k in range(maxiter): z = z*z + c if abs(z) < 2.0: return True else: return False print mandel(-0.2, 0.1) print mandel(1.0, 1.0)