Example:
div = 100
sample_size = 20
node = nuke.toNode('ColorSampler')
for i in range(24):
x = i % 6
y = i // 6 # python3から除算の解がFloatになったので、整数除算
center_x = div * x + div / 2.0
center_y = div * y + div / 2.0
value = node.sample(
'red', center_x, center_y, sample_size, sample_size)
print(i, x, y, value)
text = f'{value:.2f}'
text_node = nuke.toNode(f'Text{i+1}')
text_node['message'].setValue(text)