我当前的数据框如下所示:
midprice ema12 ema26 difference
0 0.002990 0.002990 0.002990 0.000000e+00
1 0.002990 0.002990 0.002990 4.227920e-08
2 0.003018 0.002994 0.002992 2.295777e-06
3 0.003025 0.002999 0.002994 4.579221e-06
4 0.003067 0.003009 0.003000 9.708765e-06
5 0.003112 0.003025 0.003008 1.718520e-05
我试过的是:
df.loc[:, 'action'] = np.select(condlist=[df.difference[0] < df.difference[-1] < df.difference[-2], df.ema12 < df.ema26 ], choicelist=['buy', 'sell'], default='do nothing')
因此更新列 action与 buy如果连续三次列的值 difference小于它以前的值。关于如何进行的任何想法？谢谢!
最佳答案
我认为你需要:
m1= df['difference'] < df['difference'].shift(-1)
m2= df['difference'] < df['difference'].shift(-2)
m3= df['difference'] < df['difference'].shift(-3)
df['action'] = np.select(condlist=[m1 | m2 | m3, df.ema12 < df.ema26 ],
choicelist=['buy', 'sell'],
default='do nothing')
print (df)
midprice ema12 ema26 difference action
0 0.002990 0.002990 0.002990 0.000000e+00 buy
1 0.002990 0.002990 0.002990 4.227920e-08 buy
2 0.003018 0.002994 0.002992 2.295777e-06 buy
3 0.003025 0.002999 0.002994 4.579221e-06 buy
4 0.003067 0.003009 0.003000 9.708765e-06 buy
5 0.003112 0.003025 0.003008 1.718520e-05 do nothing
关于python - Pandas:使用 if 语句更新列，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/54627750/