NetworkX と Matplotlib の使い方

次のページの最初のサンプルです。日本語を使えるようにしました。
Python networkx.draw_networkx_nodes() Examples

example_01.py

#! /usr/bin/python
#
#   example_01.py
#
#                       Apr/18/2019
# ------------------------------------------------------------------
import sys
import networkx as nx
import matplotlib
import matplotlib.pyplot as plt
# ------------------------------------------------------------------
def draw_graph(edges):
    G = nx.DiGraph()
    G.add_edges_from(edges)

    values = [1.0 for node in G.nodes()]

    # Specify the edges you want here
    edge_colours = ['black' for edge in G.edges()]
    black_edges = [edge for edge in G.edges()]

    # Need to create a layout when doing
    # separate calls to draw nodes and edges
    pos = nx.spring_layout(G)
    nx.draw_networkx_nodes(G, pos, cmap=plt.get_cmap('Reds'), node_color = values, node_size=4800)
    nx.draw_networkx_edges(G, pos, edgelist=black_edges, arrows=True)
#    nx.draw_networkx_labels(G,pos,font_size=12,font_family='sans-serif')
    nx.draw_networkx_labels(G,pos,font_size=12,font_family='TakaoExMincho')

    plt.axis('off')
    plt.show()
#
# ------------------------------------------------------------------
edges = [('明治','大正'),('大正','昭和'),('昭和','平成'), \
        ('平成','令和'),('令和','明治')]
draw_graph(edges)
# ------------------------------------------------------------------

実行結果

日本語を使えるようにするには、次のようにします。

font_family='TakaoExMincho'

次のバージョンで確認しました。

$ python
Python 3.7.3 (default, Mar 26 2019, 21:43:19) 
[GCC 8.2.1 20181127] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import networkx
>>> import matplotlib
>>> networkx.__version__
'2.2'
>>> matplotlib.__version__
'3.0.3'