Check for duplicate rows

count_dupes() returns values of by variables for which the .data has multiple rows, along with the number of rows for each combination of values.

assert_unique() throws an error if there are multiple rows for any combination of by variable values

Usage

count_dupes(.data, by, setkey = FALSE)

assert_unique(.data, by, data_chr, by_chr)

Arguments

.data

A data frame or data table

by

tidy-select. Columns in .data

setkey

Logical. Should the output be keyed by by cols?

data_chr

optional. character. You can use this argument to manually specify the name of data shown in error messages. Useful when using these functions as checks inside other functions.

by_chr

optional. character. You can use this argument to manually specify the name of by shown in error messages. Useful when using these functions as checks inside other functions.

Value

count_dupes()

A data.table with the (filtered) by columns and an additional column "n_rows" which shows the number of rows in .data having the combination of by values shown in the output row.

assert_unique()

No return value. Called to throw an error depending on the input.

Examples

df <- read.table(text = "
x y z
1 6 1
2 6 2
3 7 3
3 7 4
4 3 5
4 3 6
", header = TRUE)

count_dupes(df, c(x, y))
#>    x y n_rows
#> 1: 3 7      2
#> 2: 4 3      2

if (FALSE) {
assert_unique(df, c(x, y))
}