Plot a network using networkx and clip it into a circle

network_in_circle.py

import networkx as nx
import matplotlib.pyplot as plt
import matplotlib.patches as patches

# Generate network
N = 20
p=0.2
G = nx.erdos_renyi_graph(N,p)

# Figure
fig = plt.figure(figsize=(4,4))
ax = plt.gca()

# Draw network
pos = nx.spring_layout(G)
nx.draw(G, pos, ax=ax, node_size=90, edge_color="gray", node_color="steelblue" )

# Circle
origin = (0,0)
radius = 0.7
patch = patches.Circle(origin, 
                       radius=radius, 
                       transform=ax.transData,
                       fill=False, 
                       edgecolor="black", 
                       linewidth=2)
ax.add_patch(patch)
for c in ax.collections:
    c.set_clip_path(patch)

r = 1.2
plt.xlim([-r,r])
plt.ylim([-r,r])

# Add text
plt.text(0,-radius*1.5,"Plot subtitle", 
         horizontalalignment='center',
         fontsize=15)