> ## Documentation Index
> Fetch the complete documentation index at: https://docs.graphext.com/llms.txt
> Use this file to discover all available pages before exploring further.
# filter_duplicates
> Filter duplicate rows, keeping the first or last of each set of duplicates found only.
## Usage
The following example shows how the step can be used in a recipe.
To keep only the first row amongst a set of duplicates, identifying duplicates by inspecting
values in columns "address" and "name"
```stan theme={null}
filter_duplicates(ds, {"columns": ["address", "name"], "keep": "first"}) -> (ds_filtered)
```
General syntax for using the step in a recipe. Shows the inputs and outputs the step is expected to receive and will produce respectively. For futher details see sections below.
```stan theme={null}
filter_duplicates(ds_in: dataset, {
"param": value,
...
}) -> (ds_out: dataset)
```
## Inputs & Outputs
The following are the inputs expected by the step and the outputs it produces. These are generally
columns (`ds.first_name`), datasets (`ds` or `ds[["first_name", "last_name"]]`) or models (referenced
by name e.g. `"churn-clf"`).
An input dataset to filter.
A dataset containing the same columns as the input dataset but including or excluding the matched rows.
## Configuration
The following parameters can be used to configure the behaviour of the step by including them in
a json object as the last "input" to the step, i.e. `step(..., {"param": "value", ...}) -> (output)`.
Names of columns used to detect and filter rows containing duplicate values.
If not provided, will inspect all columns. Note that multivalued columns, i.e. those containing lists
of values will always be ignored when searching for duplicates (but will be included in the result).
Each item in array.
Which of a duplicate set of rows to keep in the result.
Specifically, whether to keep the first or last row amongst the duplicates.
Values must be one of the following:
* `first`
* `last`
if `true`, inverts the row selection.
I.e., only rows being duplicates (in the selected columns) will be included in the resulting dataset.
Row sorting before de-duplication.
E.g. when the order of first or last duplicate to retain depends on other variables. If not configured,
no sorting will be performed.
Sort column name(s).
These column(s) will be used to sort the dataset before de-duplication (if multiple, in specified order).
null.
string.
array.
Each item in array.
Whether to sort in ascending order (or in descending order if false).
If an array, must have the same length as `by` and specify the sort order for each column.
Each item in array.