R中的grepl找到与任何字符串列表匹配的匹配项

本文介绍了R中的grepl找到与任何字符串列表匹配的匹配项的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 在引用值列表时可能使用 grepl 参数，可能使用％运算符中的％？我想采取下面的数据，如果动物名称中有狗或猫，我想返回一个确定的值，比如说保持。如果它没有狗或猫，我想返回丢弃。 data 现在，如果我只需要通过严格匹配值来实现这一点，比如说猫和狗，我可以使用以下方法： 匹配< -c（cat，dog） data $ keep< - ifelse（数据$ animal％in％匹配，Keep，Discard） 但是仅使用grep或grepl指的是列表中的第一个参数： data $ keep p> 退货 警告消息：在grepl（matches，data $ animal）中：参数'pattern'的长度大于1，只有第一个元素会被使用 请注意，我在我的搜索中看到了此线索，但这看起来不起作用： 使用具有多种模式的字符向量的grep 解决方案您可以在 grepl 的正则表达式中使用或（ | ）语句。 pre $ ifelse（grepl（dog | cat，data $ animal），keep，discard）＃[1]keepkeepdiscardkeepkeepkeepkeepdiscard＃[9]keepkeepkeepkeep保留保留丢弃保留＃[17]丢弃保留保留丢弃保留保留丢弃保留＃[25 ]keepkeepkeepkeepkeepkeepkeepkeep＃[33]keepdiscardkeepdiscardkeep 保持保持＃[41]保持保持保持保持保持保持保持保持＃[49]保持 丢弃 正则表达式 dog | cat 告诉章程ular表达式引擎查找dog或cat，并返回两个匹配项。 p> Is it possible to use a grepl argument when referring to a list of values, maybe using the %in% operator? I want to take the data below and if the animal name has "dog" or "cat" in it, I want to return a certain value, say, "keep"; if it doesn't have "dog" or "cat", I want to return "discard". data <- data.frame(animal = sample(c("cat","dog","bird", 'doggy','kittycat'), 50, replace = T))Now, if I were just to do this by strictly matching values, say, "cat" and "dog', I could use the following approach:matches <- c("cat","dog")data$keep <- ifelse(data$animal %in% matches, "Keep", "Discard")But using grep or grepl only refers to the first argument in the list:data$keep <- ifelse(grepl(matches, data$animal), "Keep","Discard")returns Warning message:In grepl(matches, data$animal) : argument 'pattern' has length > 1 and only the first element will be usedNote, I saw this thread in my search, but this doesn't appear to work:grep using a character vector with multiple patterns 解决方案 You can use an "or" (|) statement inside the regular expression of grepl.ifelse(grepl("dog|cat", data$animal), "keep", "discard")# [1] "keep" "keep" "discard" "keep" "keep" "keep" "keep" "discard"# [9] "keep" "keep" "keep" "keep" "keep" "keep" "discard" "keep"#[17] "discard" "keep" "keep" "discard" "keep" "keep" "discard" "keep"#[25] "keep" "keep" "keep" "keep" "keep" "keep" "keep" "keep"#[33] "keep" "discard" "keep" "discard" "keep" "discard" "keep" "keep"#[41] "keep" "keep" "keep" "keep" "keep" "keep" "keep" "keep"#[49] "keep" "discard"The regular expression dog|cat tells the regular expression engine to look for either "dog" or "cat", and return the matches for both. 这篇关于R中的grepl找到与任何字符串列表匹配的匹配项的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！