write_parquet {nanoparquet}

Write a data frame to a Parquet file

Description

Writes the contents of an R data frame into a Parquet file.

Usage

write_parquet(
  x,
  file,
  compression = c("snappy", "gzip", "zstd", "uncompressed"),
  metadata = NULL,
  options = parquet_options()
)

Arguments

x

Data frame to write.

file

Path to the output file. If this is the string ":raw:", then the data frame is written to a memory buffer, and the memory buffer is returned as a raw vector.

compression

Compression algorithm to use. Currently "snappy" (the default), "gzip", "zstd", and "uncompressed" are supported.

metadata

Additional key-value metadata to add to the file. This must be a named character vector, or a data frame with columns character columns called key and value.

options

Nanoparquet options, see parquet_options().

Details

write_parquet() converts string columns to UTF-8 encoding by calling base::enc2utf8(). It does the same for factor levels.

Value

NULL, unless file is ":raw:", in which case the Parquet file is returned as a raw vector.

See Also

parquet_metadata(), read_parquet().

Examples

# add row names as a column, because `write_parquet()` ignores them.
mtcars2 <- cbind(name = rownames(mtcars), mtcars)
write_parquet(mtcars2, "mtcars.parquet")