r - 在 R 中剥离向量中的非 A-Z 字符

Question

我有一个包含非 A-Z 字符的用户名向量。我希望能够去掉这些字符。有人告诉我使用字母向量，但 y =x[letters] 似乎不起作用。

谢谢

Answer 1

如果 x 是您的向量，请使用一对简单的范围正则表达式与 gsub 并将所有内容替换为空字符串。使用 ^ 给出模式的否定:

gsub("[^a-zA-Z]", "", x)

例如，一些简单的数据。

 gsub("[^a-zA-Z]", "", c(letters, LETTERS, "3s8t7a2c9k:o3v8e7r%F%L^O#W%&^%@#^"))
 [1] "a"             "b"             "c"             "d"             "e"             "f"             "g"             "h"            
 [9] "i"             "j"             "k"             "l"             "m"             "n"             "o"             "p"            
[17] "q"             "r"             "s"             "t"             "u"             "v"             "w"             "x"            
[25] "y"             "z"             "A"             "B"             "C"             "D"             "E"             "F"            
[33] "G"             "H"             "I"             "J"             "K"             "L"             "M"             "N"            
[41] "O"             "P"             "Q"             "R"             "S"             "T"             "U"             "V"            
[49] "W"             "X"             "Y"             "Z"             "stackoverFLOW"