pandas 如何通过熊猫数据框获取行增量值
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How to get row delta value by pandas dataframe
提问by JustinDoghouse
I got a dataframe combined by with index = datetimeand column = {'currentprice'}
我得到了一个与index = datetime和结合的数据框column = {'currentprice'}
index currentPrice
2015-03-26 10:09:01 75.75
2015-03-26 10:11:57 75.70
Now I want to get the delta value during every 3 minutes(as an example), the I can get a dataframe like this:
现在我想每 3 分钟获取一次 delta 值（例如），我可以获得这样的数据帧：
index delta
2015-03-26 10:09:01 -0.05
2015-03-26 10:11:57 0.10
...
What should I do?
我该怎么办？
回答by Nicholas Aldershof
To expand upon the answer given in the comments, you can use
要扩展评论中给出的答案，您可以使用
df['delta'] = df.currentPrice.diff().shift(-1)
to get the difference between the price in one row and the next. However if you're actually interested in finding the difference between time periods separated by 3 minutes, not the 2m56s in your data, you're going to need to resample your timeseries using the resample method as documented here: http://pandas.pydata.org/pandas-docs/dev/timeseries.html
获得一行和下一行的价格之间的差异。但是，如果您真的有兴趣找到由 3 分钟分隔的时间段之间的差异，而不是数据中的 2m56s，则您将需要使用此处记录的 resample 方法重新采样时间序列： http://pandas。 pydata.org/pandas-docs/dev/timeseries.html
