r - 双引号和 fread 函数的问题

Question

我有一些如下所示的列条目:

c("This is just a "shame"...") # since its a character

这将在您的 C:\驱动器上写入一个文件:

sample.data <- data.frame(case1=c("This is just a 'shame'..."), 
                          case2="This is just a shame") # here I could not make it to insert the double quotes 
write.csv(sample.data, file="C:/sample_data.csv")

require(data.table)
test.fread <- fread("C:/sample_data.csv")
test.read.csv <- read.csv("C:/sample_data.csv")

如果我使用 fread 函数(来自 data.table)读取 csv 数据，我会得到他的错误:

Bumped column 79 to type character on data row 12681, field contains '   
a.n."'. Coercing previously read values in this column from logical, 
integer or numeric back to character which may not be lossless; e.g., if 
'00' and '000' occurred before they will now be just '0', and there 
may be inconsistencies with treatment of ',,' and ',NA,' too (if they 
occurred in this column before the bump). If this matters please rerun 
and set 'colClasses' to 'character' for this column. Please note that column
type detection uses the first 5 rows, the middle 5 rows and the 
last 5 rows, so hopefully this message should be very rare. 
If reporting to datatable-help, please rerun and include 
the output from verbose=TRUE.

如果我使用read.csv，则不会发生错误，并且条目会正确读取!

问题1:如何删除字符名称中的双引号。

问题2:为什么read.csv读取条目正确但fread失败？

Answer 1

正如 @Arun 善意建议的那样，目前 github 上的 data.table 开发版本 1.9.5 可能会有所帮助。

要安装，请按照以下步骤操作(需要 Rtools):

# To install development version

library(devtools)
install_github("Rdatatable/data.table", build_vignettes = FALSE)

它已经过测试，因此这是为了确认最新版本的data.table解决了双引号的问题，没有问题。

有关更多详细信息和更新，请查看以下链接 github data.table