Detect factor-like character columns (low-cardinality only)

Identifies character columns that look categorical, protecting id-like names and leading-zero codes.

Usage

detect_factors(
  data,
  max_levels = 50,
  max_unique_ratio = 0.2,
  protect_patterns = c("id$", "uid$", "code$", "ref$", "key$"),
  keep_leading_zero_chars = TRUE
)

Arguments

data

A data frame or tibble.

max_levels

Maximum distinct values for a factor candidate. Default 50.

max_unique_ratio

Maximum unique/non-NA ratio for a factor. Default 0.2.

protect_patterns

Regexes for names kept as character. Default c("id$", "uid$", "code$", "ref$", "key$").

keep_leading_zero_chars

Keep a character column when any value is a leading-zero digit string (e.g. "00123"). Default TRUE.

Value

A tibble of factor candidates: name, n, n_non_na, n_unique, unique_ratio, reason.

Examples

detect_factors(tibble::tibble(adm = c("A", "B", "A")))
#> # A tibble: 0 × 6
#> # ℹ 6 variables: name <chr>, n <int>, n_non_na <int>, n_unique <int>,
#> #   unique_ratio <dbl>, reason <chr>