<｜begin▁of▁sentence｜>### Instruction:
Given a graph which you can read from graph_file.gml, can you use the constraint() method provided by the Vertex class in igraph to calculate and print the constraint score of a specific vertex (e.g., the vertex with id 3) in the graph?
### Response:
import igraph as ig

# Assuming we have a Graph object g
# Let's read the graph from a .gml file
g = ig.read('graph_file.gml')

# To calculate the constraint for vertex with id 3
vertex_id = 3
constraint_score = g.vs[vertex_id].constraint()

# Print the constraint score of the vertex
print(f'Constraint score of vertex {vertex_id}: {constraint_score}')
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