Question

数据集包含有关超级英雄的信息。此代码从字符串'name'中删除恼人的括号部分：

# package loading
library(fivethirtyeight)

# data opening
data(package ="fivethirtyeight")
data(comic_characters)

for (i in 1:length(comic_characters$name)) 
{
  bracket[i]                <-  which(strsplit(comic_characters$name[i], "")[[1]] == "(")
  comic_characters$name[i]  <-  substr(comic_characters$name[i], start = 1, stop = bracket[i]-2)
}

如何使用apply函数（没有for循环）做同样的事情？这是我尝试的方式：

     bracket = sapply(sapply(strsplit(comic_characters$name, ''), function(x) 
    which(x == '(')), `[`, 1)  

    # here comes the problem:
        comic_characters$name <- lapply(x, function(x)
 substr(comic_characters$name, start=1, stop=bracket[i]-2))

我该怎么做？提前谢谢！

Answer 1

这不会达到同样的目的吗？

df <- data.frame(comic_characters)
df$name <- sub("\\(.*", "", df$name)

Answer 2

您可以使用stringr包来实现目标。

# package loading
library(fivethirtyeight)
library(stringr)

# data opening
data(package ="fivethirtyeight")
data(comic_characters)

# remove text enclosed in brackets from character names
cleaned_character_names <- str_replace_all(
  string = comic_characters$name,
  pattern = "\\(.*\\)",
  replacement = ""
)

# trim whitespace from start and ending of the character names
cleaned_character_names <- str_trim(
  string = cleaned_character_names
)

某些字符名称有两个用括号括起来的部分，例如：＆＃34;盗贼（安娜玛丽）（地球-616）＆＃34;。上面的代码将删除＆＃34;（Anna Marie）＆＃34;和＃34;（地球-616）＆＃34;从角色名称。

如何在R中应用substring函数？

2 个答案: