User: code a block placing / removing game like minecraft very early versions in python using moderngl and glfw.

Assistant: Creating a basic block-placing and removing game similar to early versions of Minecraft involves several steps. We'll use `moderngl` for OpenGL rendering and `glfw` for window management. Here's a very simplified implementation to get you started. Note that this code focuses on setting up the environment and rendering cubes. For simplicity, we'll work with a single cube and allow you to add/move cubes based on key inputs.

Before running this code, you'll need to install the required packages using pip:

```sh
pip install moderngl glfw
```

And here’s a basic implementation:

```python
import glfw
import moderngl
import numpy as np
from pyrr import Matrix44

# Window dimensions
WIDTH, HEIGHT = 800, 600

# Initialize GLFW
if not glfw.init():
    raise Exception("GLFW can't be initialized")

# Create the window
window = glfw.create_window(WIDTH, HEIGHT, "Block Game", None, None)
if not window:
    glfw.terminate()
    raise Exception("GLFW window can't be created")

# Make the window's context current
glfw.make_context_current(window)

# Initialize ModernGL context
ctx = moderngl.create_context()

# Simple vertex and fragment shaders
vertex_shader = """
#version 330
uniform mat4 model;
uniform mat4 projection;

in vec3 in_vert;

void main() {
    gl_Position = projection * model * vec4(in_vert, 1.0);
}
"""

fragment_shader = """
#version 330
out vec4 fragColor;

void main() {
    fragColor = vec4(0.6, 0.3, 0.1, 1.0);
}
"""

prog = ctx.program(vertex_shader=vertex_shader, fragment_shader=fragment_shader)

# Vertex data for a simple cube
vertices = np.array([
    # Front face
    -0.5, -0.5,  0.5,
     0.5, -0.5,  0.5,
     0.5,  0.5,  0.5,
    -0.5,  0.5,  0.5,
    # Back face
    -0.5, -0.5, -0.5,
     0.5, -0.5, -0.5,
     0.5,  0.5, -0.5,
    -0.5,  0.5, -0.5,
], dtype='f4')

indices = np.array([
    # Front face
    0, 1, 2, 2, 3, 0,
    # Top face
    3, 2, 6, 6, 7, 3,
    # Back face
    7, 6, 5, 5, 4, 7,
    # Bottom face
    4, 5, 1, 1, 0, 4,
    # Left face
    4, 0, 3, 3, 7, 4,
    # Right face
    1, 5, 6, 6, 2, 1,
], dtype='i4')

vbo = ctx.buffer(vertices.tobytes())
ibo = ctx.buffer(indices.tobytes())
vao = ctx.simple_vertex_array(prog, vbo, 'in_vert', index_buffer=ibo)

# Define the perspective and model transformations
projection = Matrix44.perspective_projection(45.0, WIDTH / HEIGHT, 0.1, 1000.0)
prog['projection'].write(projection.astype('f4'))

def main():
    # Main loop
    cube_position = np.array([0, 0, -3.0])

    while not glfw.window_should_close(window):
        glfw.poll_events()

        # Clear the screen
        ctx.clear(0.2, 0.3, 0.3)

        # Handle key inputs to move cube
        if glfw.get_key(window, glfw.KEY_W) == glfw.PRESS:
            cube_position[2] += 0.1
        if glfw.get_key(window, glfw.KEY_S) == glfw.PRESS:
            cube_position[2] -= 0.1
        if glfw.get_key(window, glfw.KEY_A) == glfw.PRESS:
            cube_position[0] -= 0.1
        if glfw.get_key(window, glfw.KEY_D) == glfw.PRESS:
            cube_position[0] += 0.1

        model = Matrix44.from_translation(cube_position)
        prog['model'].write(model.astype('f4'))

        # Render the cube
        vao.render()

        # Swap buffers
        glfw.swap_buffers(window)

    # Cleanup
    glfw.terminate()

if __name__ == "__main__":
    main()
```

### Key Points:

- **GLFW** is used for window creation and input handling.
- **ModernGL** provides a context for OpenGL rendering.
- **Pyrr** is used to manage matrix operations.
- The code renders a simple 3D cube and allows movement using the W, A, S, and D keys.

This is a basic setup to help you get started. Enhancements required to fully emulate early Minecraft-like features include managing a grid of blocks, implementing view frustum culling, and handling more complex input for block placement and removal.
User: modify the code to not use pyrr
Assistant: