Question

我有一个代码（我得到它here）：

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？

Answer 1

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

让我们解释正则表达式术语：

\ b在称为“单词边界”的位置匹配。这场比赛是零长度。
[a-zA-Z0-9]：字母数字
{4,10}：{min，max}

如果你想得到这个的否定，你把它放在（）之间，你拿// 1

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

“你好！#London是gr8。我真的很喜欢这里的东西！珠穆朗玛峰的alcomb很棒！前面提到的地方很棒！#Wow”

很有趣的是，在2 regexpr中存在4个字母的单词。

Answer 2

# 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

Answer 3

gsub(" [^ ]{1,3} | [^ ]{11,} "," ",m)
[1] "Hello! #London gr8. really here! alcomb Mount Everest excellent! aforementioned
     place amazing! #Wow"

Answer 4

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!"

Answer 5

来自Alaxender＆amp;的答案。 agstudy：

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

立即行动！

非常感谢，伙计！

Answer 6

我不熟悉R并且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，模式就像这样

[^A-z0-9]([A-z0-9]{1,3}|[A-z0-9]{11,})[^A-z0-9]

使用正则表达式在R中提取特定长度的单词

6 个答案: