10

我有一个类似的代码（我在这里得到）：

m<- c("Hello! #London is gr8. I really likewhatishappening here! The alcomb of Mount Everest is excellent! the aforementioned place is amazing! #Wow")

x<- gsub("\\<[a-z]\\{4,10\\}\\>","",m)
x

我尝试了其他方法，比如

m<- c("Hello! #London is gr8. I really likewhatishappening here! The alcomb of Mount Everest is excellent! the aforementioned place is amazing! #Wow")

x<- gsub("[^(\\b.{4,10}\\b)]","",m)
x

我需要删除长度小于 4 或大于 10 的单词。我哪里错了？

4

6 回答 6

12 
  gsub("\\b[a-zA-Z0-9]{4,10}\\b", "", m) 
 "! # is gr8. I  likewhatishappening ! The  of   is ! the aforementioned  is ! #Wow"

让我们解释一下正则表达式术语：

  1. \b 在称为“单词边界”的位置匹配。这个匹配是零长度的。
  2. [a-zA-Z0-9]：字母数字
  3. {4,10}：{最小，最大}

如果你想得到这个的否定，你把它放在 between() 和你拿 //1

gsub("([\\b[a-zA-Z0-9]{4,10}\\b])", "//1", m)

“你好！#London 是 gr8。我真的很喜欢这里发生的事情！珠穆朗玛峰的 alcomb 很棒！前面提到的地方太棒了！#Wow”

有趣的是，在 2 个正则表达式中存在 4 个字母的单词。

于 2012-12-10T09:11:12.020 回答
1

来自 Alaxender & agstudy 的答案：

x<- gsub("\\b[a-zA-Z0-9]{1,3}\\b|\\b[a-zA-Z0-9]{10,}\\b", "", m)

现在工作！

非常感谢，伙计！

于 2012-12-10T09:56:22.047 回答
1 
# starting string
m <- c("Hello! #London is gr8. I really likewhatishappening here! The alcomb of Mount Everest is excellent! the aforementioned place is amazing! #Wow")

# remove punctuation (optional)
v <- gsub("[[:punct:]]", " ", m)

# split into distinct words
w <- strsplit( v , " " )

# calculate the length of each word
x <- nchar( w[[1]] )

# keep only words with length 4, 5, 6, 7, 8, 9, or 10
y <- w[[1]][ x %in% 4:10 ]

# string 'em back together
z <- paste( unlist( y ), collapse = " " )

# voila
z
于 2012-12-10T09:02:05.677 回答
1 
gsub(" [^ ]{1,3} | [^ ]{11,} "," ",m)
[1] "Hello! #London gr8. really here! alcomb Mount Everest excellent! aforementioned
     place amazing! #Wow"
于 2012-12-10T09:08:14.947 回答
1

这可能会让你开始：

m <- c("Hello! #London is gr8. I really likewhatishappening here! The alcomb of Mount Everest is excellent! the aforementioned place is amazing! #Wow")
y <- gsub("\\b[a-zA-Z0-9]{1,3}\\b", "", m) # replace words shorter than 4
y <- gsub("\\b[a-zA-Z0-9]{10,}\\b", "", y) # replace words longer than 10
y <- gsub("\\s+\\.\\s+ ", ". ", y) # replace stray dots, eg "Foo  .  Bar" -> "Foo. Bar"
y <- gsub("\\s+", " ", y) # replace multiple spaces with one space
y <- gsub("#\\b+", "", y) # remove leftover hash characters from hashtags
y <- gsub("^\\s+|\\s+$", "", y) # remove leading and trailing whitespaces
y
# [1] "Hello! London. really here! alcomb Mount Everest excellent! place amazing!"
于 2012-12-10T09:09:24.997 回答
0

我不熟悉 R，也不知道它在正则表达式模式中支持哪些类或其他功能。没有它们，模式将是这样的

[^A-z0-9]([A-z0-9]{1,3}|[A-z0-9]{11,})[^A-z0-9]
于 2012-12-10T08:40:51.760 回答