使用write.csv时如何防止行名写入文件？

Question

命令：

t <- data.frame(v = 5:1, v2 = 9:5)
write.csv(t, "t.csv")

生成的文件：

# "","v","v2"
# "1",5,9
# "2",4,8
# "3",3,7
# "4",2,6
# "5",1,5

我该如何防止将带有行索引的第一列写入文件？

- watbywbarif

Answer 1

write.csv(t, "t.csv", row.names=FALSE)

来自 ?write.csv：

row.names: either a logical value indicating whether the row names of
          ‘x’ are to be written along with ‘x’, or a character vector
          of row names to be written.

- NPE

---

我感到惭愧，因为我尝试了'write.csv'，但是...谢谢aix！ - watbywbarif

译文：是的，诀窍在于理解这一列代表行名称。 - Vanuan

也许应该重新命名它。 - stephanmg

有没有办法将row.names = FALSE设置为默认值？在复杂的管道中，当单个脚本使用TRUE默认值时，总是会引起头痛... - Adrarc

Answer 2

为了完整起见，readr包中的write_csv()更快且不会写入行名称。

# install.packages('readr', dependencies = TRUE)
library(readr)
write_csv(t, "t.csv")

如果您需要将大型数据写出，请使用data.table包中的fwrite()。它比write.csv和write_csv都快得多。

# install.packages('data.table')
library(data.table)
fwrite(t, "t.csv")

以下是Edouard在他的网站上发布的基准测试

microbenchmark(write.csv(data, "baseR_file.csv", row.names = F),
               write_csv(data, "readr_file.csv"),
               fwrite(data, "datatable_file.csv"),
               times = 10, unit = "s")

## Unit: seconds
##                                              expr        min         lq       mean     median         uq        max neval
##  write.csv(data, "baseR_file.csv", row.names = F) 13.8066424 13.8248250 13.9118324 13.8776993 13.9269675 14.3241311    10
##                 write_csv(data, "readr_file.csv")  3.6742610  3.7999409  3.8572456  3.8690681  3.8991995  4.0637453    10
##                fwrite(data, "datatable_file.csv")  0.3976728  0.4014872  0.4097876  0.4061506  0.4159007  0.4355469    10

- Tung