human
I wrote the below code

    count = [0]
    def residual(P):
        count[0] += 1
        d2x = zeros_like(P)
        d2y = zeros_like(P)
        d2x[1:(-1)] = ((((P[2:] - (2 * P[1:(-1)])) + P[:(-2)]) / hx) / hx)
        d2x[0] = ((((P[1] - (2 * P[0])) + P_left) / hx) / hx)
        d2x[(-1)] = ((((P_right - (2 * P[(-1)])) + P[(-2)]) / hx) / hx)
        d2y[:, 1:(-1)] = ((((P[:, 2:] - (2 * P[:, 1:(-1)])) + P[:, :(-2)]) / hy) / hy)
        d2y[:, 0] = ((((P[:, 1] - (2 * P[:, 0])) + P_bottom) / hy) / hy)
        d2y[:, (-1)] = ((((P_top - (2 * P[:, (-1)])) + P[:, (-2)]) / hy) / hy)
        return ((d2x + d2y) + (5 * (cosh(P).mean() ** 2)))
    if preconditioning:
        M = get_preconditioner()
    else:
        M = None
    guess = zeros((nx, ny), float)
    sol = root(residual, guess, method='krylov', options={'disp': True, 'jac_options': {'inner_M': M}})
    print ('Residual', abs(residual(sol.x)).max())
    print ('Evaluations', count[0])
    return sol.x

What's a good function header?
 ... What is a Python program to print ('Residual', abs(residual(sol?
assistant
#Here is Python program to print ('Residual', abs(residual(sol.

def solve(preconditioning=True):