r - 当数据不在表中时，如何将文本文件读入 R

Question

我有一个很长的电话日志作为文本文件，我试图将它读入 R 但它并没有真正奏效。文本具有结构，但它肯定不是表格。其结构如下

每条记录由多行组成，所以 readLines 不太合适

每条记录的每一行都是一个单独的字段

某些记录在第二个字段之后有一个额外的字段

每条新记录都用空行标注。如果可以指定记录由“\n\n”分隔并且字段(或列)由“\n”分隔，那么 readLines 或 scan 会起作用

下面是一个例子:

TheInstitute 5467
  telephone line 4125526987 x 4567
  datetime 2011110516 12:56
  blay blay blah who knows what, but anyway it may have a comma

TheInstitute 5467
  telephone line 4125526987 x 4567
  datetime 2011110516 12:58
  blay blay blah who knows what

TheInstitute 5467
  telephone line 412552999 x 4999
  bump phone line 4125527777
  datetime 2011110516 12:59
  blay blay blah who knows what

TheInstitute 5467
  telephone line 4125526987 x 4567
  bump phone line 4125527777
  datetime 2011110516 13:51
  blay blay blah who knows what, but anyway it may have a comma

TheInstitute 5467
  telephone line 4125526987 x 4567
  datetime 2011110516 14:56
  blay blay blah who knows what

我怎样才能在 R 中做到这一点？我尝试过扫描、粘贴、strsplit 等技巧，但我一直在绕圈子旋转。我可能必须将它放入一个列表中，因为它可以处理不等数量的元素。我想让所有记录都具有相同数量的字段，对于那些没有一个字段的记录(这里称为凹凸电话)，我希望它们只是将 NA 作为该字段中的值。即使只是开始，我也将不胜感激。从那里我可以玩耍和玩具。

Answer 1

当 scan 函数中的 multi.line = TRUE 时，记录应以两个行尾结束。我在您的文件周围使用 textConnection 执行此操作，但您将使用有效的文件名:

inp <- scan(textConnection(txt), multi.line=TRUE, 
             what=list(place="character", tline1="character", 
             cline1="character", cline2 ="character", cline3="character"), sep="\n")
Read 5 records
> str(as.data.frame(inp))
'data.frame':   5 obs. of  5 variables:
 $ place : Factor w/ 1 level "TheInstitute 5467": 1 1 1 1 1
 $ tline1: Factor w/ 2 levels "  telephone line 4125526987 x 4567",..: 1 1 2 1 1
 $ cline1: Factor w/ 4 levels "  bump phone line 4125527777",..: 2 3 1 1 4
 $ cline2: Factor w/ 4 levels "  blay blay blah who knows what",..: 2 1 3 4 1
 $ cline3: Factor w/ 3 levels "","  blay blay blah who knows what",..: 1 1 2 3 1
> as.data.frame(inp)
              place                             tline1
1 TheInstitute 5467   telephone line 4125526987 x 4567
2 TheInstitute 5467   telephone line 4125526987 x 4567
3 TheInstitute 5467    telephone line 412552999 x 4999
4 TheInstitute 5467   telephone line 4125526987 x 4567
5 TheInstitute 5467   telephone line 4125526987 x 4567
                        cline1
1    datetime 2011110516 12:56
2    datetime 2011110516 12:58
3   bump phone line 4125527777
4   bump phone line 4125527777
5    datetime 2011110516 14:56
                                                           cline2
1   blay blay blah who knows what, but anyway it may have a comma
2                                   blay blay blah who knows what
3                                       datetime 2011110516 12:59
4                                       datetime 2011110516 13:51
5                                   blay blay blah who knows what
                                                           cline3
1                                                                
2                                                                
3                                   blay blay blah who knows what
4   blay blay blah who knows what, but anyway it may have a comma
5