How to create a diff. between the current value and the previous value

Technical Analysis
1

Hi,



How to create a diff. between the current value and the value of 2 periods before in the below code:



df['RSI_14'] = talib.RSI(df['Close'], timeperiod=14)



I want to add a column in the df that shows how much RSI has changed in Last three periods. and the drop RSI column



Thanks

2

Hello Ashish,



You can get the difference between the value at the current bar and 2 bars prior using the diff function. You can also save it in a new column as shown below.



df['RSI_change'] = df['RSI_14'].diff(period=2)



The old column can be deleted like this:



df.drop(['RSI_14'],axis=1,inplace=True)



For reference:

pandas.DataFrame.diff — pandas 2.2.3 documentation

 

pandas.DataFrame.drop — pandas 2.2.3 documentation

3

I am getting the folloing error when using the above function:

 

diff() got an unexpected keyword argument 'period'
4

Hello Ashish,



You can directly pass the number like this:



df['RSI_14'].diff(2)