R read.table vs read.csv

Question

grades <- read.table("studentgrades.csv",header = TRUE,row.names="StudentID", sep = ",")

gradess <- read.csv("studentgrades.csv",header = TRUE,row.names="StudentID", sep = ",")

read.table的结果是：

grades
[1] First          Last           Math           Science        Social.Studies
<0 rows> (or 0-length row.names)

read.csv的结果是：

gradess
   First       Last Math Science Social.Studies
11   Bob      Smith   90      80             67
12  Jane      Weary   75      NA             80
10   Dan "Thornton"   65      75             70
40  Mary    O'Leary   90      95             92

我只是不知道为什么read.tables不能给我正确的结果。

Answer 1

该问题是由于O'Leary of last name列中的quote (')引起的。您需要更改read.table中的默认quote选项，该选项在默认情况下设置为(')，以获得所需的结果。

如果您在read.table中使用quote=NULL，如下所示

grades <- read.table("studentgrades.csv",header = TRUE,sep=",",quote=NULL,row.names="StudentID")

然后你就会得到想要的结果。

> grades
    First        Last Math  Science Social.Studies
11    Bob       Smith   90       80             67
12   Jane       Weary   75       NA             80
10    Dan  "Thornton"   65       75             70
40   Mary     O'Leary   90       95             92