# databricks.koalas.Series.expanding¶

Series.expanding(min_periods=1) → databricks.koalas.window.Expanding

Provide expanding transformations.

Note

‘min_periods’ in Koalas works as a fixed window size unlike pandas. Unlike pandas, NA is also counted as the period. This might be changed in the near future.

Parameters
min_periodsint, default 1

Minimum number of observations in window required to have a value (otherwise result is NA).

Returns
a Window sub-classed for the particular operation