import pandas as pd
df = pd.DataFrame({'a':[1,2,3,4,5,6,7,8,9,10],
'b':[11,12,13,14,15,16,17,18,19,20],
})
pd.rolling_mean(df,window = 2)
AttributeError: module 'pandas' has no attribute 'rolling_mean'
pandas document http://pandas.pydata.org/pandas-docs/version/0.17.0/generated/pandas.rolling_mean.html
I do know why i get this error, pandas docement show this information. And I can not use it ? Indeed,all the method like this happened same problem eg:(pandas.rolling_median) (pandas.rolling_var)
By the way, argument ''window'' , how to use it?