Question

如何删除所有字符＆＃34; p＆＃34;和＆＃34; p＆＃34;本身，在v1的所有字符串中，如下面的数据框中那样。

df1 <- data.frame(v1 = c("m0p1", "m5p30", "m11p20", "m59p60"))

如何删除所有字符＆＃34; p＆＃34;和＆＃34; p＆＃34;本身？谢谢

Answer 1

您可以使用gsub

# Remove everything before p
gsub("^.*?p(.*)","\\1",df1$v1,perl=TRUE)
#[1] "1"  "30" "20" "60"

# Remove everything after p
gsub("(.*)?p.*$","\\1",df1$v1,perl=TRUE)
# [1] "m0"  "m5"  "m11" "m59"

Answer 2

您也可以

sub('^[^p]*p', '', df1$v1)
#[1] "1"  "30" "20" "60"

或者

sub('p.*$', '', df1$v1)
#[1] "m0"  "m5"  "m11" "m59"

Answer 3

在p：

之后

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Untitled Document</title>

<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">

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<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>

</head>

<body>

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</button>

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<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
  <div class="modal-dialog">
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      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <h4 class="modal-title" id="myModalLabel">Modal title</h4>
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        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
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  </div>
</div>

</body>
</html>

在p：

之前

gsub('.*(?<=p)(\\d+)','\\1',df1$v1,perl=T)

根据R中特定字符的相对位置从字符串中删除字符

3 个答案: