Pandas: I want to create a column in a Time Series where the value depends on the previous row's value

Question

I have a time series dataframe where I need to create a boolean-valued column, which is

• True if the current value is more than 10% different from the previous row's value.
• False otherwise

Answer 1

As you have not provided any sample data, so I am not 100% sure, what you exactly want. But here is what I think you need to do

df=pd.DataFrame([np.random.randn(10,1)],columns=['first'])
df['prev']=df.shift(1)
df['prev']-df['first']>df['first']*0.1