Tidy the column names of an ingested table — clean_column

Converts names to a consistent, syntactically valid form: transliterated to ASCII, non-alphanumerics collapsed to a single separator, and duplicates disambiguated with a numeric suffix. The counterpart of janitor::clean_names().

Usage

clean_column_names(
  data,
  case = c("snake", "lower_camel", "upper_camel", "screaming_snake", "none"),
  sep = "_"
)

Arguments

data: A data frame, or a character vector of names.
case: "snake" (default), "lower_camel", "upper_camel", "screaming_snake", or "none" to normalise separators only.
sep: Separator for "snake" and "screaming_snake" (default "_") .

Value

The data frame with new names (and an "original_names" attribute), or the cleaned character vector.

Details

Open-data extracts arrive with names like "Total Population (2021)" and "% change", which need backticks everywhere and break silently when a re-release renames "% change" to "% change". Normalising once at ingestion makes the schema stable against that.

Record the mapping in the capsule manifest. Cleaning names changes what a downstream script must refer to, so an unrecorded cleaning is itself a reproducibility hazard – the returned object carries the original names in its "original_names" attribute for exactly that.

Examples

clean_column_names(c("Total  Population (2021)", "% change",
                     "Ville / City", "dup", "dup"))
#> [1] "total_population_2021" "pct_change"            "ville_city"           
#> [4] "dup"                   "dup_2"                

# Applied to a data frame, with the original names retained.
df <- data.frame(`Total Pop` = 1:2, `% change` = 3:4,
                 check.names = FALSE)
cleaned <- clean_column_names(df)
names(cleaned)
#> [1] "total_pop"  "pct_change"
attr(cleaned, "original_names")
#> [1] "Total Pop" "% change" 

# Other cases.
clean_column_names(c("Total Pop"), case = "lower_camel")
#> [1] "totalPop"
clean_column_names(c("Total Pop"), case = "upper_camel")
#> [1] "TotalPop"
clean_column_names(c("Total Pop"), case = "screaming_snake")
#> [1] "TOTAL_POP"