Question

给定字符字符字符串

test_1<-"abc def,ghi klm"
test_2<-"abc, def ghi klm"

我希望获得

"abc"
"def"
"ghi"

然而,使用strsplit,人们必须知道弦中分解值的顺序,因为strsplit使用第一个值来进行第一个分解,第二个值来进行第二个分解,然后进行再循环。

但是,这并不:

strsplit(test_1, c(",", " "))
strsplit(test_2, c(" ", ","))

strsplit(test_2, split=c("[:punct:]","[:space:]"))[[1]]

我想在任何我发现我分裂价值的地方一步一步地把弦分开

Answer 1

事实上, strsplit 也使用 grep 模式。 (一个逗号是一个regex 元字符, 而一个空格则不是; 因此在模式参数参数中需要双重排除逗号。因此, 使用 < code>\s > 将比必要性更有助于改进可读性 :

> strsplit(test_1, "\, |\,| ")  # three possibilities OR ed
[[1]]
[1] "abc" "def" "ghi" "klm"

> strsplit(test_2, "\, |\,| ")
[[1]]
[1] "abc" "def" "ghi" "klm"

不同时使用和 (注意SO没有显示的额外空间), 你就会得到一些字符( 0) 值。如果我写了的话, 可能更清楚:

> strsplit(test_2, "\,\s|\,|\s")
[[1]]
[1] "abc" "def" "ghi" "klm"

@Fojtasek如此正确:使用字符类往往会简化任务,

> strsplit(test_2, "[, ]+")
[[1]]
[1] "abc" "def" "ghi" "klm"

> strsplit(test_1, "[, ]+")
[[1]]
[1] "abc" "def" "ghi" "klm"

Answer 2

如果您不喜欢正则表达式, 您可以多次调用 strsplit () :

strsplits <- function(x, splits, ...)
{
    for (split in splits)
    {
        x <- unlist(strsplit(x, split, ...))
    }
    return(x[!x == ""]) # Remove empty values
}

strsplits(test_1, c(" ", ","))
# "abc" "def" "ghi" "klm"
strsplits(test_2, c(" ", ","))
# "abc" "def" "ghi" "klm"

添加示例的 < 强度 > 更新

strsplits(test_1, c("[[:punct:]]","[[:space:]]"))
# "abc" "def" "ghi" "klm"
strsplits(test_2, c("[[:punct:]]","[[:space:]]"))
# "abc" "def" "ghi" "klm"

但如果您要使用正则表达式, 您最好使用 @DWins 方法 :

strsplit(test_1, "[[:punct:][:space:]]+")[[1]]
# "abc" "def" "ghi" "klm"
strsplit(test_2, "[[:punct:][:space:]]+")[[1]]
# "abc" "def" "ghi" "klm"

Answer 3

您可以使用 strsplit( 测试_ 1, "\W") 。

Answer 4

 test_1<-"abc def,ghi klm"
 test_2<-"abc, def ghi klm"
 key_words <- c("abc","def","ghi")
 matches <- str_c(key_words, collapse ="|")
 str_extract_all(test_1, matches)
 str_extract_all(test_2, matches)

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