How to write an indicator equivalent to pandas.expanding().mean()?

[soulmachine]

I've read the following source code:

https://github.com/mementum/backtrader/blob/master/backtrader/indicators/basicops.py

It seems every indicator has a period.

I found no way to implement an indicator with the following logic:

import pandas as pd
data = pd.Series([1.0, 2.0, 3.0, 4.0])
indicators = data.expanding(2).mean()

Any ideas? Thanks

[ab_trader]

I assume that equivalent will be this formula in the next():

value = sum(self.data.close.get(size=len(self.data)))/len(self.data)

[soulmachine]

@ab_trader It works, thanks!

[soulmachine]

I implemented the EWMAC strategy from the book "Systematic Trading" by Robert Carver, Jupyter notebook: https://github.com/soulmachine/crypto-notebooks/blob/master/backtest/backtrader-EWMAC.ipynb