将列表的元素转换为表格

Question

在使用 pdftools 包读取 R 中的 pdf 后，我得到一个列表，其中列表的每个元素都有一个类似表的结构，我想将维护其表结构的列表的每个元素聚合到一个数据框中.

这里有一个生成的 txt 文件的链接： https://drive.google.com/open?id=0Bydt25g6hdY-b0NwaDF1NWE0NkU

我试过这个：

table <- list(0)
for (i in test5) { table <- append(table, i)}

但我得到了相同的列表。

我希望能够将它作为一个表格，其中每一列都是一个变量，每一行都是一个观察值，如果可能的话删除日期行，这样它就不会干扰列。

这是dput(table[1:3])的输出

list("                                                                          ", 
c("\r\n Thu 04/21/2016              ", "\r\n  _No Call Type Attached                               0   00:00    00:00     00:00     00:00    00:00       0     0%      0%  00:00     00:00\r\n  IEX Billing English                         12.5%    1   03:17    00:55     00:03     04:15    00:00       2   200%      0%  00:27     00:00      1  100%\r\n  IEX VOB English                             50.0%    4   03:15    01:29     01:12     05:57    00:00       1    25%      0%  05:56     00:00      4  100%\r\n  IEX VOB Spanish                             37.5%    3   03:59    00:20     00:28     04:48    00:00       3   100%      0%  00:20     00:00      3  100%\r\n "
), "\r\n")

Answer 1

考虑使用readLines() 扫描文档，然后用空格分割行以迁移到字符列表中。几个Filter() 调用用于删除单字符和空元素。

file <- "C:\\Path\\To\\Text.txt"

# CONNECT TO FILE, READ LINES
con <- file(description=file, open="r")
pdftext <- readLines(con, warn=FALSE)
close(con)

# FILTER OUT ONE-CHARACTER ELEMENTS
pdftext <- Filter(function(x) nchar(x)>1, pdftext)

# SPLIT LINES BY WHITESPACE / FILTER ONE-CHARACTER ELEMENTS
datalines <- lapply(pdftext, function(x) {
                 tmp <- strsplit(x, "\\s+")[[1]]
                 Filter(function(l) nchar(l)>1, tmp)
})

# FILTER EMPTY ELEMENTS
datalines <- Filter(length, datalines)

# FILL IN NAs TO FIT TABLE COLS (USING 16, LARGEST LENGTH)
datalines <- lapply(datalines, function(x) {
  if(length(x) < 16) {  x <- c(x, rep(NA, 16 - length(x)))
  } else {
    x
  }
})

# BIND ALL LINES INTO CHARACTER MATRIX
datamatrix <- do.call(rbind, datalines)

输出

#       [,1]  [,2]         [,3]      [,4]       [,5]     [,6]     [,7]       [,8]       [,9]       [,10]      [,11]    [,12]  
#  [1,] "Thu" "04/21/2016" "Direct"  "Internal" "Calls:" "Direct" "External" "Calls:"   "Outbound" "Calls:"   NA       NA     
#  [2,] "_No" "Call"       "Type"    "Attached" "00:00"  "00:00"  "00:00"    "00:00"    "00:00"    "0%"       "0%"     "00:00"
#  [3,] "IEX" "Billing"    "English" "12.5%"    "03:17"  "00:55"  "00:03"    "04:15"    "00:00"    "200%"     "0%"     "00:27"
#  [4,] "IEX" "VOB"        "English" "50.0%"    "03:15"  "01:29"  "01:12"    "05:57"    "00:00"    "25%"      "0%"     "05:56"
#  [5,] "IEX" "VOB"        "Spanish" "37.5%"    "03:59"  "00:20"  "00:28"    "04:48"    "00:00"    "100%"     "0%"     "00:20"
...