joinspy (version 0.7.3)

key_duplicates: Find Duplicate Keys

Description

Identifies rows with duplicate values in the specified key columns. Returns a data frame containing only the rows with duplicated keys, along with a count of occurrences.

Usage

key_duplicates(data, by, keep = c("all", "first", "last"))

Value

A data frame containing the duplicated rows, with an additional column .n_duplicates showing how many times each key appears. Returns an empty data frame (0 rows) if no duplicates found.

Arguments

data

A data frame.

by

A character vector of column names to check for duplicates.

keep

Character. Which duplicates to return:

"all"

Return all rows with duplicated keys (default)

"first"

Return only the first occurrence of each duplicate

"last"

Return only the last occurrence of each duplicate

See Also

key_check(), join_spy()

Examples

df <- data.frame(
  id = c(1, 2, 2, 3, 3, 3, 4),
  value = letters[1:7]
)

# Find all duplicates
key_duplicates(df, by = "id")

# Find first occurrence only
key_duplicates(df, by = "id", keep = "first")