I struggled for a while with the syntax to work for calculating a rolling function by group for a dask dataframe. The documentation is excellent, but in this case does not have an example.
The working version I have is as follows, from a csv that contains a text field with User ids and and x, y, and z column:
ddf = read_csv('./*.csv')
ddf.groupby(ddf.User).x.apply(lambda x: x.rolling(5).mean(), meta=('x', 'f8')).compute()
Is this the recommended syntax for rolling functions applied by group within dask DataFrames, or is there a recommended alternative?
See Question&Answers more detail:
os 与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…