cum_count_where
cum_count_where performs a cumulative count of values that pass a set of filters in an update_by table operation.
Syntax
Parameters
| Parameter | Type | Description |
|---|---|---|
| col | str | The name of the column that will contain the count of values that pass the filters. |
| filters | Union[str, Filter, Sequence[str], Sequence[Filter]] | Formulas for filtering as a list of Strings. Any filter is permitted, as long as it is not refreshing and does not use row position/key variables or arrays. |
Tip
Providing multiple filter strings in the filters parameter results in an AND operation being applied to the filters. For example, "Number % 3 == 0", "Number % 5 == 0" returns the count of values where Number is evenly divisible by both 3 and 5. You can also write this as a single conditional filter ("Number % 3 == 0 && Number % 5 == 0") and receive the same result.
You can use the || operator to OR multiple filters. For example, Y == `M` || Y == `N` matches when Y equals M or N.
Returns
An UpdateByOperation to be used in an update_by table operation.
Examples
The following example performs an update_by on the source table using the cum_count_where operation
and counting rows where Y is >= 20 and < 99. No grouping columns are given, so the cumulative count is calculated for all rows in the table.
The following example builds off the previous by specifying Letter as the grouping column. Thus, the cumulative count includes rows where Y is >= 20 and < 99 and is calculated for each unique letter.
In the next example, cum_count_where returns the number of rows where Letter equals 'A' and Y > 50 over the entire table (without grouping).
This example returns the number of rows where Y is between 50 and 100 (inclusive), as grouped by Letter and X.