import pandas as pd
import networkx as nx
import matplotlib.pyplot as plt

p_graph = nx.Graph()

p_graph.add_node("A")
p_graph.add_node("B")
p_graph.add_node("C")
p_graph.add_node("D")
p_graph.add_node("E")
p_graph.add_node("F")
p_graph.add_edge("A", "B")
p_graph.add_edge("A", "C")
p_graph.add_edge("B", "C")
p_graph.add_edge("B", "D")
p_graph.add_edge("C", "D")
p_graph.add_edge("D", "F")
p_graph.add_edge("D", "E")
p_graph.add_edge("C", "F")


assert len(p_graph.nodes()) == 6
assert len(p_graph.edges()) == 8

nx.draw(p_graph)
plt.show()
