正则表达式用嵌套引号解析csv

Possible Duplicate:
07000
07001

我知道这个问题已经问了很多次,但有不同的答案;我很困惑.

我的行是：

1,3.2,BCD,"qwer 47"" ""dfg""",1

可选的引用和双引号MS Excel标准. (数据：qwer 47“”dfg“表示如下”qwer 47“”“”dfg“”“.)

我需要一个正则表达式.

好的,你从评论中看到正则表达式不是正确的工具.但如果你坚持,这里有：

这个正则表达式将在Java(或.NET和其他支持占有量词和冗长正则表达式的实现)中工作：

^            # Start of string
(?:          # Match the following:
 (?:         #  Either match
  [^",\n]*+  #   0 or more characters except comma,quote or newline
 |           #  or
  "          #   an opening quote
  (?:        #   followed by either
   [^"]*+    #    0 or more non-quote characters
  |          #   or
   ""        #    an escaped quote ("")
  )*         #   any number of times
  "          #   followed by a closing quote
 )           #  End of alternation,#  Match a comma (separating the CSV columns)
)*           # Do this zero or more times.
(?:          # Then match
 (?:         #  using the same rules as above
  [^",\n]*+  #  an unquoted CSV field
 |           #  or a quoted CSV field
  "(?:[^"]*+|"")*"
 )           #  End of alternation
)            # End of non-capturing group
$           # End of string

Java代码：

boolean foundMatch = subjectString.matches(
    "(?x)^         # Start of string\n" +
    "(?:           # Match the following:\n" +
    " (?:          #  Either match\n" +
    "  [^\",\\n]*+ #   0 or more characters except comma,quote or newline\n" +
    " |            #  or\n" +
    "  \"          #   an opening quote\n" +
    "  (?:         #   followed by either\n" +
    "   [^\"]*+    #    0 or more non-quote characters\n" +
    "  |           #   or\n" +
    "   \"\"       #    an escaped quote (\"\")\n" +
    "  )*          #   any number of times\n" +
    "  \"          #   followed by a closing quote\n" +
    " )            #  End of alternation\n" +
    ",#  Match a comma (separating the CSV columns)\n" +
    ")*            # Do this zero or more times.\n" +
    "(?:           # Then match\n" +
    " (?:          #  using the same rules as above\n" +
    "  [^\",\\n]*+ #  an unquoted CSV field\n" +
    " |            #  or a quoted CSV field\n" +
    "  \"(?:[^\"]*+|\"\")*\"\n" +
    " )            #  End of alternation\n" +
    ")             # End of non-capturing group\n" +
    "$            # End of string");

请注意,您不能假设CSV文件中的每一行都是完整的行.您可以在CSV行中包含换行符(只要包含换行符的列用引号括起来).这个正则表达式知道这一点,但如果你只给它一个部分行,它就会失败.这是您真正需要CSV解析器来验证CSV文件的另一个原因.这就是解析器的作用.如果您控制输入并且知道在CSV字段中永远不会有换行符,那么您可能会放弃它,但只有这样.

正则表达式用嵌套引号解析csv

相关推荐