正则表达式以匹配CSV文件的嵌套引号

Question

I know this has been discussed a million times. I tried searching through the forums and have seen some close regex expressions and tried to modify them but to no avail.

Say there is a line in a CSV file like this:

"123", 456, "701 "B" Street", 910
                 ^^^

Is there an easy regex to detect "B" (since it's a non-escaped set of quotes within the normal CSV quotes) and replace it with something like \\"B\\" ? The final string would end up looking like this:

"123", 456, "701 \"B\" Street", 910

Help would be greatly appreciated!

Answer 1

Trust me you don't want to do this with regex. You want something like Java CSV Library .

Answer 2

(?<!^)(?<!",)(?<!\d,)"(?!,")(?!,\d)(?!$)(?!,-\d)

我使它起作用，以为如果有人在寻找答案，我会发布它

Answer 3

There are a few zillion libraries to help you parse CSV, but if you're wanting to use a regexp for academic reasons, this may help:

• quoted string with escape support. "(\\\\.|[^\\\\"])*"
• unquoted field: [^",]*
• delimiter: , *

I don't use CSV files, so I'm not sure about the 'other csv field' validity (matching 456, for example above), or whether /, */ is the delimiter you want..

At any rate, combining the above will match one field and one delimiter (or end of string):

(quotedstring|unquoted)(delimiter|$)

Answer 4

我将使用量身定制的sed表达式作为

's/\(.*\),\(.*\),\(.*\)"\(.*\)\" \(.*\),\(.*\)/\1,\2,\3 \4 \5 \6/g'

Answer 5

Your example is not proper CSV:

"123", 456, "701 "B" Street", 910

this should actually be:

"123", 456, "701 ""B"" Street", 910

(There are plenty of variations of CSV, of course, but since most of the time people want it for use with excel or access I stick to the Microsoft definition.)

Therefore the regex for this can look like:

".+("").+("").+"

The groups (in parentheses) will be your double quotes, and the rest ensures that they are found within another set of quotes.

That covers the find part of your needs. The replace part depends on what you are programming in.