npi_flatten.npi_results: Flatten NPI search results

In npi: Access the U.S. National Provider Identifier Registry API

Flatten NPI search results

Description

This function takes an npi_results S3 object returned by npi_search and flattens its list columns. It unnests the lists columns and left joins them by npi. You can optionally specify which columns from df to include.

Usage

## S3 method for class 'npi_results'
npi_flatten(df, cols = NULL, key = "npi")

Arguments

df	A data frame containing the results of a call to npi_search.
cols	If non-NULL, only the named columns specified here will be be flattened and returned along with npi.
key	A quoted column name from df to use as a matching key. The default value is "npi".

Details

The names of unnested columns are prefixed by the name of their originating list column to avoid name clashes and show their lineage. List columns containing all NULL data will be absent from the result because there are no columns to unnest. All input keys are retained even when their selected nested data is empty, regardless of the order of cols. If all selected nested data is empty, only the keys are returned. When multiple nested tables have more than one row for a key, their rows are combined in all possible combinations.

Value

A data frame (tibble) with flattened list columns.

Examples

# Flatten all list columns
data(npis)
npi_flatten(npis)

# Only flatten specified columns
npi_flatten(npis, cols = c("basic", "identifiers"))

npi documentation built on Sept. 6, 2026, 9:06 a.m.