Matplotlib：在与寄生虫轴相连的数据上绘制数据标签

Question

这是我在SO上看到的几个地方的'如何绘制数据标签'问题的变体。但是，我从未在寄生虫轴上看到它。

基本上，我希望连接到寄生虫（右）垂直轴的时间序列（绿色）的每个点上方的数据标签。

这就是我目前的情况：

from mpl_toolkits.axes_grid1 import host_subplot
import matplotlib.pyplot as plt

times=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23]
plotorder=[239, 133, 94, 42, 31, 27, 49, 99, 172, 292, 397, 439, 450, 391, 429, 374, 382, None, None, None, None, None, None, None]
lastyearorders=[119, 78, 49, 29, 14, 12, 30, 46, 108, 154, 194, 224, 181, 199, 213, 186, 167, 152, 135, 115, 99, 106, 97, 90]
difference=[100.8, 70.5, 91.8, 44.8, 121.4, 125.0, 63.3, 115.2, 59.3, 89.6, 104.6, 96.0, 148.6, 96.5, 101.4, 101.1, 128.7, None, None, None, None, None, None, None]
ordersMax=max(plotorder+lastyearorders)
growthMax=max(difference)

host = host_subplot(111)

par = host.twinx()
host.set_xlabel("Hour")
host.set_ylabel("Orders")
par.set_ylabel("% Growth")
host.set_xlim(0,24)
host.set_ylim(0,ordersMax*1.1)
par.set_ylim(0,growthMax*2)
p1, = host.plot(times, plotorder, linewidth=2, marker='o', color='r', label="Today's Orders")
p1, = host.plot(times, lastyearorders, linewidth=2, color='b', label="LY Orders")
p2, = par.plot(times, difference, marker='s', color='green', label="% Growth")
leg = plt.legend()
plt.show()

我已尝试同时使用par.plot_text(times[1], difference[1], difference[1])和par.annotate()，但两者都提出错误AttributeError: 'AxesParasite' object has no attribute 'plot_text'

这就是我目前所拥有的：

我想要这样的东西（来自Excel）：

Answer 1

for (x,y) in zip(times, difference):
    if y:
         par.annotate("{0}%".format(y), xy=(x, y+10))

这似乎对我有用，你尝试注释了什么？