Grab any keys associated to an epi_df

Grab any keys associated to an epi_df

Usage

key_colnames(x, ...)

# Default S3 method
key_colnames(x, ...)

# S3 method for class 'data.frame'
key_colnames(x, other_keys = character(0L), exclude = character(0L), ...)

# S3 method for class 'epi_df'
key_colnames(x, exclude = character(0L), ...)

# S3 method for class 'epi_archive'
key_colnames(x, exclude = character(0L), ...)

Arguments

x

a data.frame, tibble, or epi_df

...

additional arguments passed on to methods

other_keys

an optional character vector of other keys to include

exclude

an optional character vector of keys to exclude

Value

If an epi_df, this returns all "keys". Otherwise NULL.