Shading in Blender

ShadingInBlender.py

import bpy
ob = bpy.context.object # get the active object
mesh = ob.data
for area in bpy.context.screen.areas:
  if area.type == 'VIEW_3D':
    for space in area.spaces:
      if space.type == 'VIEW_3D':
        space.viewport_shade = 'MATERIAL'
        
bpy.context.scene.game_settings.material_mode = 'GLSL'
VertexShader = ""
FragmentShader = """
void main() {
    gl_FragColor = vec4(0.6, 1.0, 0.0, 1.0);
}
"""

for mat in mesh.materials:
  shader = mat.getShader()
  shader.setSource(VertexShader, FragmentShader, 1)