readr (version 1.0.0)

write_delim: Save 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)
write_csv(x, path, na = "NA", append = FALSE, col_names = !append)
write_excel_csv(x, path, na = "NA", append = FALSE, col_names = !append)
write_tsv(x, path, na = "NA", append = FALSE, col_names = !append)
format_csv(x, na = "NA", append = FALSE, col_names = !append)
format_tsv(x, na = "NA", append = FALSE, col_names = !append)
format_delim(x, delim, na = "NA", append = FALSE, col_names = !append)
output_column(x)

Arguments

x

A data frame to write to disk

path

Path to write to.

delim

Delimiter used to seperate values. Defaults to " ". 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?

Value

write_* returns the input x invisibly, format_* returns a string.

Output

Factors are coerced to character. Doubles are formatted using the grisu3 algorithm. POSIXct's are formatted as ISO8601. All columns are encoded as UTF-8. write_excel_csv also includes a UTF-8 Byte order mark which indicates to Excel the csv is UTF-8 encoded. Values are only quoted if needed: if they contain a comma, quote or newline.

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

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))