R：为 grepl 粘贴数据框列

Question

我在 R 中有两行代码理论上应该做同样的事情我想用它们在列中设置一个值

a <- paste(ref.dg.safe[,'safewords'], collapse="|")
"c(\"NO BATTERIES\", \"COSTUME\", \"CABLE\", \"BAG\", \"CLOTHING\)"

b <- paste(ref.dg.safe$safewords, collapse="|")  
NO BATTERIES|COSTUME|CABLE|BAG|CLOTHING|

我想要第二个输出使用第一行代码，因为当我在函数中使用 "b" 时出现部分匹配错误

我也想了解为什么输出如此不同

更新：

最初我使用

行导入数据集

ref.dg.safe <- unique(tbl_df(read.csv("~/Projects/foo_project/REF_SafeList.txt", sep = "\t", as.is = TRUE, strip.white=TRUE)))

dput 看起来像

structure(list(safewords = c("NO BATTERIES", "COSTUME", "CABLE", 
"BAG", "CLOTHING", "BRACELET", "FAUCET", "IRON", "CASE", "NO BATTERY", 
"BELT", "JACKET", "CONVERTER", "HAIR", "GLASS", "SHOE", "ROUTER", 
"LABEL", "ADAPTOR", "SILICONE", "EARPHONE", "SPONGE", "WOOD", 
"TANKTOP", "WALLET", "TUBE", "TRIPODS", "STONE", "LAMP", "HEADPHONES", 
"COOKIECUTTERS", "CONVERTERS", "COWLEATHER", "INFLATABLETOY", 
"HEADPHONE", "LABLE", "ROMPER", "POLE", "PROBE", "FIBEROPTIC", 
"APRON", "TABLECLOTH", "AVR", "TABLEBASE", "DESK", "BEAUTYGOODS", 
"SEAT", "NOBATTERIES", "SHEOS", "CHARGERS", "STAPLER", "SATCHEL"
)), .Names = "safewords", class = c("tbl_df", "data.frame"), row.names  =     c(NA, 
-52L))

Answer 1

回答原因：

> class(df[,"safewords"])
[1] "tbl_df"     "data.frame"
> class(df$safewords)
[1] "character"

这是由于 [ 和 $ 运算符的工作方式以及它们如何强制 return 或不强制（我不知道如何总结这一点，看看在 data.frame 和子集运算符的文档中）。

一个解决方法是让第一个表单松散它的 data.frame 状态 unlist 像这样：

> paste(unlist(df[,"safewords"]),collapse="|")
[1] "NO BATTERIES|COSTUME|CABLE|BAG|CLOTHING|BRACELET[...]"

我删除了部分输出以使其在此处可读

R：为 grepl 粘贴数据框列

R: Paste a dataframe column for grepl

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