bach.DataFrame.expanding

expanding​

(min_periods=1, center=False)

​[source]

Create an expanding window starting with the first row in the group, with at least min_period observations. The result will be right-aligned in the window.

To use grouping as well, first call group_by() on this frame and call rolling on the result.

Parameters​

  • min_periods (int) – the minimum amount of observations in the window before a value is reported.
  • center (bool) – whether to center the result, currently not supported.
note

The DataFrame is required to be sorted in order to avoid non-determinist results.

Raises​

Exception – If DataFrame.order_by is empty.