Question

我有一个看起来像这样的文本文件：

"Saved at:19 January 2015, 1:01 PM"
"Course"    "Time"  
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:28 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:27 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:26 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:25 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:02 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:02 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"
The DI Module Exam contains 16 mul..."
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"

在使用read.delim时，我指定了skip=1，然后使用第二行作为标题。有时，在导入过程中应该跳过像第11行（可能是其他任何东西）的行。我想，如果有办法，特别是在R基地，

跳过第一行，
将第二行作为标题和
跳过不以"EDPY 301 (SEM J4 Wi14)"开头的行。

仅供参考，这是我用来导入文本文件的代码：

read.delim("path to the file",header=T,stringsAsFactors=FALSE,strip.white=TRUE,na.strings=c("NA",""),skip=1)

谢谢，

Answer 1

我不知道有条件地使用read.table排除行，但是使用readLines读取并使用grep或grepl创建包含向量似乎有效：

Lines <- readLines(textConnection('"Saved at:19 January 2015, 1:01 PM"
"Course"    "Time"  
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:28 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:27 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:26 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:25 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:02 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 7:02 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"
The DI Module Exam contains 16 mul..."
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"
"EDPY 301 (SEM J4 Wi14)"    "28 January 2014, 6:57 PM"'))

good <- grep("^\\\"EDPY", Lines)
inp <- read.table(text=Lines[good], col.names = c("Course","Time" ))

模式字符串需要在行开头标记后有三个斜杠，两个用于斜杠，第三个用于转义双引号。

在保留标题的同时导入文本文件的特定行

1 个答案: