import pandas as pd
import matplotlib.pyplot as plt  

data = [{'a':1,'b':1},{'a':2,'b':2},{'a':3,'b':5},
        {'a':4,'b':8},{'a':5,'b':9},{'a':6,'b':6},
        {'a':7,'b':5},{'a':8,'b':2},{'a':9,'b':9},
        {'a':10,'b':1}]
df = pd.DataFrame(data)
plt.plot(df.index,df['b']);
highmask = df[df.b > 3]

# plt.plot(highmask.index,highmask['b'],color='red');

# linestyle=''  不画线 
plt.plot(highmask.index,highmask['b'],color='red',linestyle='',marker='*');




# 买入信号
buymask = df[df['bias250']< -15]
plt.plot(buymask['dt'],buymask['close'],color='red',linestyle='',marker='o')

# 卖出信号
sellmask = df[df['bias250'] > 20]
plt.plot(sellmask['dt'],sellmask['close'],color='g',linestyle='',marker='o')