Add bar chart for Laplacian Centrality

testing pandas to_dict, and streamlit bar_chart

app.py

@@ -108,4 +108,6 @@ return_value = agraph(nodes=nodes,
                       config=config)
 
 st.markdown('The Laplacian centrality is a measure of closeness')
-st.write(str(nx.laplacian_centrality(G)))
+st.write(str(nx.laplacian_centrality(G)))
+df_lc = pd.from_dict(nx.laplacian_centrality(G))
+st.bar_chart(df_lc)