英文:
Golang Regex: FindAllStringSubmatch to []string
问题
我从Amazon S3下载了一个多行文件，格式如下：
ColumnAv1 ColumnBv1 ColumnCv1 ...
ColumnAv2 ColumnBv2 ColumnCv2 ...
该文件的类型是字节类型。然后我想用正则表达式解析它：
matches := re.FindAllSubmatch(file,-1)
然后我想逐行将结果传递给一个以[]string作为输入的函数（string[0]是ColumnAv1，string[1]是ColumnBv2，...）。
我应该如何将[][][]byte的结果转换为包含第一行、第二行等的[]string？我想我应该在循环中进行操作，但我无法使其正常工作：
for i:=0;i<len(len(matches);i++{
tmp:=myfunction(???)
}
顺便问一下，为什么FindAllSubmatch函数返回[][][]byte而FindAllStringSubmatch函数返回[][]string？
（很抱歉，我现在无法访问我的真实示例，所以语法可能不正确）
英文:
I download a multiline file from Amazon S3 in format like:
ColumnAv1 ColumnBv1 ColumnCv1 ...
ColumnAv2 ColumnBv2 ColumnCv2 ...
the file is of type byte. Then I want to parse this with regex:
matches := re.FindAllSubmatch(file,-1)
then I want to feed result row by row to function which takes []string as input (string[0] is ColumnAv1, string[1] is ColumnBv2, ...).
How should I convert result of [][][]byte to []string containing first, second, etc row? I suppose I should do it in a loop, but I cannot get this working:
for i:=0;i<len(len(matches);i++{
tmp:=myfunction(???)
}
BTW, Why does function FindAllSubmatch return [][][]byte whereas FindAllStringSubmatch return [][]string?
(Sorry I don't have right now access to my real example, so the syntax may not be proper)
答案1
得分: 3
这些内容的翻译如下：
在包的文档中详细解释了这一切。
阅读解释如下的段落：
> 有16种正则表达式匹配和识别匹配文本的方法。它们的名称由这个正则表达式匹配：
>
> Find(All)?(String)?(Submatch)?(Index)?
在你的情况下，你可能想使用FindAllStringSubmatch。
在Go中，string只是一个只读的[]byte。
你可以选择继续传递[]byte变量，
或者将[]byte值转换为string：
var byteSlice = []byte{'F','o','o'}
var str string
str = string(byteSlice)
英文:
It's all explained extensively in the package's documentation.
Read the parapgraph which explains :
> There are 16 methods of Regexp that match a regular expression and identify the matched text. Their names are matched by this regular expression:
>
> Find(All)?(String)?(Submatch)?(Index)?
In your case, you probably want to use FindAllStringSubmatch.
In Go, a string is just a read-only []byte.
You can choose to either keep passing []byte variables around,
or cast the []byte values to string :
var byteSlice = []byte{'F','o','o'}
var str string
str = string(byteSlice)
答案2
得分: 1
你可以通过两个嵌套循环来遍历字节结果，就像遍历字符串结果一样，并且在第二个循环中将字节片段转换为字符串：
package main
import "fmt"
func main() {
f := [][][]byte{{{'a', 'b', 'c'}}}
for _, line := range f {
for _, match := range line { // match 是 []byte 类型
fmt.Println(string(match))
}
}
}
英文:
You can simply iterate through the bytes result as you would do for strings result using two nested loop, and just convert slice of bytes to a string in the second loop:
package main
import "fmt"
func main() {
f := [][][]byte{{{'a', 'b', 'c'}}}
for _, line := range f {
for _, match := range line { // match is a type of []byte
fmt.Println(string(match))
}
}
}
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