4

所以，我真的需要帮助做一件愚蠢的事情，但显然我自己无法做到。

我在具有这种格式的文件中有一组行（less在 OSX 上读取）：

XXXXXXXX^GT^XXXXXXXX^G\N^G0^GDL^G\N^G2018-09-14 13:57:00.0^G2018-09-16 00:00:00.0^GCompleted^G\N^G\N^G1^G2018-09-16 21:41:02.267^G1^G2018-09-16 21:41:02.267^GXXXXXXX^G\N
YYYYYYYY^GS^XXXXXXXX^G\N^G0^GDL^G\N^G2018-08-29 00:00:00.0^G2018-08-29 23:00:00.0^GCompleted^G\N^G\N^G1^G2018-09-16 21:41:03.797^G1^G2018-09-16 21:41:03.81^GXXXXXXX^G\N

所以分隔符是BEL分隔符，我正在以这种方式加载 CSV：

val df = sqlContext.read.format("csv")
  .option("header", "false")
  .option("inferSchema", "true")
  .option("delimiter", "\u2407")
  .option("nullValue", "\\N")
  .load("part0000")

但是当我阅读它时，它只是以这种方式将行读取为一列：

XXXXXXXXCXXXXXXXX\N0DL\N2018-09-15 00:00:00.02018-09-16 00:00:00.0Completed\N\N12018-09-16 21:41:03.25712018-09-16 21:41:03.263XXXXXXXX\N
XXXXXXXXSXXXXXXXX\N0DL\N2018-09-15 00:00:00.02018-09-15 23:00:00.0Completed\N\N12018-09-16 21:41:03.3712018-09-16 21:41:03.373XXXXXXXX\N

似乎有一个unkown character（你什么也看不到，只是因为我在 stackoverflow 上对其进行了格式化）代替^G.

更新：这可能是对 scala 火花的限制吗？如果我以这种方式使用 scala 运行代码：

val df = sqlContext.read.format("csv")
  .option("header", "false")
  .option("inferSchema", "true")
  .option("delimiter", "\\a")
  .option("nullValue", "\\N")
  .load("part-m-00000")

display(df)

我长胖了

java.lang.IllegalArgumentException: Unsupported special character for delimiter: \a

而如果我使用 python 运行：

df = sqlContext.read.format('csv').options(header='false', inferSchema='true', delimiter = "\a", nullValue = '\\N').load('part-m-00000')

display(df)

一切都很好！

4

1 回答 1

2

在 spark-scala 中这些版本看起来有限制，这是代码中支持的 csv 分隔符，

apache/spark/sql/catalyst/csv/CSVOptions.scala

val delimiter = CSVExprUtils.toChar(
    parameters.getOrElse("sep", parameters.getOrElse("delimiter", ",")))

---CSVExprUtils.toChar

apache/spark/sql/catalyst/csv/CSVExprUtils.scala

  def toChar(str: String): Char = {
(str: Seq[Char]) match {
  case Seq() => throw new IllegalArgumentException("Delimiter cannot be empty string")
  case Seq('\\') => throw new IllegalArgumentException("Single backslash is prohibited." +
    " It has special meaning as beginning of an escape sequence." +
    " To get the backslash character, pass a string with two backslashes as the delimiter.")
  case Seq(c) => c
  case Seq('\\', 't') => '\t'
  case Seq('\\', 'r') => '\r'
  case Seq('\\', 'b') => '\b'
  case Seq('\\', 'f') => '\f'
  // In case user changes quote char and uses \" as delimiter in options
  case Seq('\\', '\"') => '\"'
  case Seq('\\', '\'') => '\''
  case Seq('\\', '\\') => '\\'
  case _ if str == """\u0000""" => '\u0000'
  case Seq('\\', _) =>
    throw new IllegalArgumentException(s"Unsupported special character for delimiter: $str")
  case _ =>
    throw new IllegalArgumentException(s"Delimiter cannot be more than one character: $str")
}
于 2019-01-12T14:56:24.770 回答