python 中的简单移动平均线

Question

I am new to python. May I ask, for example the following codes, how do I know there is an attribute of mean function following the rolling function? (I am not sure if I said this correctly syntaxically) Thank you guys.

data['SMA50'] = data['SP500'].rolling(50).mean()

Answer 1

I assume that data is a pandas data frame. To find the methods available, I first look at the documentation for rolling() :

Returns: a Window or Rolling sub-classed for the particular operation

In the left-hand menu, I see a link for Window . Clicking on this link shows all the available methods for Rolling .

Answer 2

In general, in order to understand an API (in this case, Pandas), you need to read its documentation (in one of many forms, perhaps a tutorial ).

Technically, though, you can use the builtin dir function .

Assuming data is a DataFrame, then

dir(data['SP500'])

will tell you that there is a rolling method, and

dir(data.rolling(50))

will tell you that there is a mean method.

You can also use the builtin help function .