readr (version 1.3.1)

write_delim: Write a data frame to a delimited file

Description

This is about twice as fast as write.csv(), and never writes row names. output_column() is a generic method used to coerce columns to suitable output.

Usage

write_delim(x, path, delim = " ", na = "NA", append = FALSE,
  col_names = !append, quote_escape = "double")
write_csv(x, path, na = "NA", append = FALSE, col_names = !append,
  quote_escape = "double")
write_csv2(x, path, na = "NA", append = FALSE, col_names = !append,
  quote_escape = "double")
write_excel_csv(x, path, na = "NA", append = FALSE,
  col_names = !append, delim = ",", quote_escape = "double")
write_excel_csv2(x, path, na = "NA", append = FALSE,
  col_names = !append, delim = ";", quote_escape = "double")
write_tsv(x, path, na = "NA", append = FALSE, col_names = !append,
  quote_escape = "double")

Arguments

x

A data frame to write to disk

path

Path or connection to write to.

delim

Delimiter used to separate values. Defaults to " " for write_delim(), "," for write_excel_csv() and ";" for write_excel_csv2(). Must be a single character.

na

String used for missing values. Defaults to NA. Missing values will never be quoted; strings with the same value as na will always be quoted.

append

If FALSE, will overwrite existing file. If TRUE, will append to existing file. In both cases, if file does not exist a new file is created.

col_names

Write columns names at the top of the file? Must be either TRUE or FALSE.

quote_escape

The type of escaping to use for quoted values, one of "double", "backslash" or "none". You can also use FALSE, which is equivalent to "none". The default is to double the quotes, which is the format excel expects.

Value

write_*() returns the input x invisibly.

Output

Factors are coerced to character. Doubles are formatted using the grisu3 algorithm. POSIXct's are formatted as ISO8601 with a UTC timezone Note: POSIXct objects in local or non-UTC timezones will be converted to UTC time before writing.

All columns are encoded as UTF-8. write_excel_csv() and write_excel_csv2() also include a UTF-8 Byte order mark which indicates to Excel the csv is UTF-8 encoded.

write_excel_csv2() and write_csv2 were created to allow users with different locale settings save csv files with their default settings ; as column separator and , as decimal separator. This is common in some European countries.

Values are only quoted if needed: if they contain a comma, quote or newline.

The write_*() functions will automatically compress outputs if an appropriate extension is given. At present, three extensions are supported, .gz for gzip compression, .bz2 for bzip2 compression and .xz for lzma compression. See the examples for more information.

References

Florian Loitsch, Printing Floating-Point Numbers Quickly and Accurately with Integers, PLDI '10, http://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf

Examples

# NOT RUN {
tmp <- tempfile()
write_csv(mtcars, tmp)
head(read_csv(tmp))

# format_* is useful for testing and reprexes
cat(format_csv(head(mtcars)))
cat(format_tsv(head(mtcars)))
cat(format_delim(head(mtcars), ";"))

df <- data.frame(x = c(1, 2, NA))
format_csv(df, na = ".")

# Quotes are automatically as needed
df <- data.frame(x = c("a", '"', ",", "\n"))
cat(format_csv(df))

# A output connection will be automatically created for output filenames
# with appropriate extensions.
dir <- tempdir()
write_tsv(mtcars, file.path(dir, "mtcars.tsv.gz"))
write_tsv(mtcars, file.path(dir, "mtcars.tsv.bz2"))
write_tsv(mtcars, file.path(dir, "mtcars.tsv.xz"))
# }