python 用 matplotlib 绘制复合饼图（子母图）

1、import

import matplotlib as mpl
import matplotlib.pyplot as plt
from matplotlib.patches import ConnectionPatch

2、绘制图形

# 使图表元素中正常显示中文
mpl.rcParams['font.sans-serif'] = 'SimHei'
# 使坐标轴刻度标签正常显示负号
mpl.rcParams['axes.unicode_minus'] = False

# 画布
fig = plt.figure(figsize=(12, 6),
                 facecolor='cornsilk'
                )
ax1 = fig.add_subplot(121)
ax2 = fig.add_subplot(122)
fig.subplots_adjust(wspace=0)

# 定义数据
data = {'category': ['子', '丑', '寅', '卯', '辰'],
        'quantity': [138, 181, 118, 107, 387]
       }

others = {'category': ['甲', '乙', '丙'],
          'quantity': [98, 170, 119]
         }

# 大饼图
labs = data['category']
quantity = data['quantity']
explode = (0, 0, 0, 0, 0.03)    # 分裂距离

ax1.pie(x=quantity,
        colors=['r', 'g', 'm', 'c', 'y'],
        explode=explode,
        autopct='%1.1f%%',
        startangle=70,
        labels=labs,
        textprops={'color': 'k',
                   'fontsize': 12,
                  }
       )

# 小饼图
labs2 = others['category']
quantity_2 = others['quantity']

ax2.pie(x=quantity_2,
        colors=['khaki', 'olive', 'gold'],
        autopct='%1.1f%%',
        startangle=70,
        labels=labs2,
        radius=0.5,
        shadow=True,
        textprops={'color': 'k',
                   'fontsize': 12,
                  },
       )

# 用 ConnectionPatch 画出两个饼图的间连线
## 饼图边缘的数据
theta1 = ax1.patches[-1].theta1
theta2 = ax1.patches[-1].theta2
center = ax1.patches[-1].center
r = ax1.patches[-1].r

width=0.2
# 上边缘的连线
x = r*np.cos(np.pi/180*theta2)+center[0]
y = np.sin(np.pi/180*theta2)+center[1]
con_a = ConnectionPatch(xyA=(-width/2,0.5), xyB=(x,y),
                        coordsA='data', coordsB='data',
                        axesA=ax2, axesB=ax1
                       )

# 下边缘的连线
x = r*np.cos(np.pi/180*theta1)+center[0]
y = np.sin(np.pi/180*theta1)+center[1]
con_b = ConnectionPatch(xyA=(-width/2,-0.5), xyB=(x,y),
                        coordsA='data', coordsB='data',
                        axesA=ax2, axesB=ax1
                       )

for con in [con_a, con_b]:
    con.set_linewidth(1)    # 连线宽度
    con.set_color=([0,0,0])    # 连线颜色
    ax2.add_artist(con)   # 添加连线

图形效果：