r - 如何删除 df 中非常特殊的字符

Question

我有一个 df，其中有一个特殊字符。我想删除它，但不知道如何删除。我已经尝试过[:graph:] , [:print:]和<U+00AE> 。但没有任何作用。我应该怎么办？有没有一种方法可以一次性删除数据集中的类似问题，例如 ® ？

df<-structure(list(df = structure(c(1L, 4L, 2L, 3L), .Label = c("Cabozantinib", 
"Left nephrectomy", "Left Superficial Inguinal Lymph Node Dissection", 
"XmAb<U+00AE>20717 (Duet-2 study - a humanized bispecific monoclonal antibody that binds PD1 and CTLA4)"
), class = "factor")), class = "data.frame", row.names = c(NA, 
-4L))

Answer 1

如果打算删除这些字符，请使用模式来匹配 <U接下来是 + (元字符 - 转义 \\ )，后跟一个或多个不是 > 的字符( [^>]+ ) 和 >在str_remove_all删除所有出现的该模式子字符串

library(stringr)
df$df <- str_remove_all(df$df, "<U\\+[^>]+\\>")
df$df
[1] "Cabozantinib"                                                                                  
[2] "XmAb20717 (Duet-2 study - a humanized bispecific monoclonal antibody that binds PD1 and CTLA4)"
[3] "Left nephrectomy"                                                                              
[4] "Left Superficial Inguinal Lymph Node Dissection"              

---

如果我们仍然想打印那些 unicode 字符

library(stringi)
stri_unescape_unicode(str_replace_all(df$df, "<U\\+([^>]+)\\>", "\\\\u\\1"))
[1] "Cabozantinib"                                                                                   
[2] "XmAb®20717 (Duet-2 study - a humanized bispecific monoclonal antibody that binds PD1 and CTLA4)"
[3] "Left nephrectomy"                                                                               
[4] "Left Superficial Inguinal Lymph Node Dissection"