AttributeError：模块“pandas”没有属性“ewmstd”

Question

I get the error message: AttributeError: module 'pandas' has no attribute 'ewmstd'

I have seen exactly the same issue for the EWM function in a previous stackoverflow post with the solution as follows:

df = pd.ewm(halflife=0.5).mean()

I therefore replicate exactly the same solution (which works for ewm ) aside from replacing ewm with ewmstd as follows:

df = pd.ewmstd(halflife=0.5).mean()

However, i get the same error message. I also try different variants, but get the same error.

Have i called the function incorrectly or how does one call it? (i use the docs from here: https://pandas.pydata.org/pandas-docs/version/0.17.0/generated/pandas.ewmstd.html

Answer 1

I have used df = pd.ewm(halflife=0.5).std() which yields results on the DataFrame. Might i expect this to provide the same output?