A CSVFileFormat is a FileFormat subclass which holds information about how to
read and parse the files included in a CSV Dataset.
Factory
CSVFileFormat$create() can take options in the form of lists passed through as parse_options,
read_options, or convert_options parameters. Alternatively, readr-style options can be passed
through individually. While it is possible to pass in CSVReadOptions, CSVConvertOptions, and CSVParseOptions
objects, this is not recommended as options set in these objects are not validated for compatibility.
Examples
# Set up directory for examples
tf <- tempfile()
dir.create(tf)
on.exit(unlink(tf))
df <- data.frame(x = c("1", "2", "NULL"))
write.table(df, file.path(tf, "file1.txt"), sep = ",", row.names = FALSE)
# Create CsvFileFormat object with Arrow-style null_values option
format <- CsvFileFormat$create(convert_options = list(null_values = c("", "NA", "NULL")))
open_dataset(tf, format = format)
#> FileSystemDataset with 1 csv file
#> x: int64
# Use readr-style options
format <- CsvFileFormat$create(na = c("", "NA", "NULL"))
open_dataset(tf, format = format)
#> FileSystemDataset with 1 csv file
#> x: int64