Python 加点坐标有大神能不能帮一下

Question

import numpy as npimport pandas as pdimport matplotlib.pyplot as plt%matplotlib inlinedata = pd.read_csv("/resources/data/zr.csv") #导入文件by_year = data.groupby(["Year description"]).size()by_year.plot(kind = "line",alpha=1,figsize = [10,7],color = 'c',\title = "The number of cancers that accompanied the increase in years increased",\linewidth=3)plt.ylabel("Disease discovery")plt.grid(True)                     #加上校准线plt.subplots_adjust(bottom=0.2)    #设置图像高度plt.margins(0.1)                   #居中显示图像  #for a, b in zip():     #plt.text()      #有没有大神会在这两行加上每一年的点坐标