openGL: Turn the whole scene or "orbiting" the camera

OpenGL seems as a nice library with a good community. After following some tutorials and reading some explanations I had the feeling I got the basics.

Still, I struggling with the camera. I get that with OpenGL the camera is static and that to create the illusion the camera is moving you have to move the whole scene. I tried to turn the whole scene. The objects turn, but the front object stays at the front. I read some more, but it feels that I am doing what they are telling me.

Here is a running example of two squares I like to "orbit" with the camera.

import pygame
from pygame.locals import *
from OpenGL.GL import *
from OpenGL.GLU import *


def draw():
    glBegin(GL_QUADS)
    glColor3fv((1,0,0))
    glVertex3fv((1,-1,-1))
    glVertex3fv((1,1,-1))
    glVertex3fv((-1,1,-1))
    glVertex3fv((-1,-1,-1))

    glColor3fv((0,1,0))
    glVertex3fv((1,-1,-2))
    glVertex3fv((1,1,-2))
    glVertex3fv((-1,1,-2))
    glVertex3fv((-1,-1,-2))

    glEnd()

pygame.init()
display = (800,600)
pygame.display.set_mode(display, DOUBLEBUF|OPENGL)

gluPerspective(45, (display[0]/display[1]), 0.1, 50.0)

glTranslatef(0.0,0.0, -25.0)

while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glRotatef(1, 0.0, 1.0, 0.0)

        draw()
        pygame.display.flip()
        pygame.time.wait(10)

Now both squares turn, but the green squares stays in front of the red square. What I would like to see is that the whole scene turns, so that the green square moves behind the red square. Could someone point me into the right direction?

You have to enable GL_DEPTH_TEST with glEnable(GL_DEPTH_TEST);.

Also, using the old fixed function pipeline is deprecated (As of OpenGL 3.0) and has been deleted in OpenGL 3.1. I highly recommend you not to start a new project with this old fixed pipeline.