ruby - 正则表达式匹配三个字母并删除三个字母

Question

我一直在试图弄清楚一个正则表达式来只输出三个字母并删除“not”这个词

到目前为止我尝试过的是:

• .gsub(/^[A-z]+$/)(仍然输出和下面一样)

• 我还在 this post about Regex 上尝试了一切

这是我需要正则表达式的内容:

bash: line 1: drs: command not found
bash: line 2: tep: command not found
bash: line 3: ldo: command not found
bash: line 4: tep: command not found
bash: line 5: txw: command not found
bash: line 6: tep: command not found
bash: line 7: jfp: command not found
bash: line 8: mys: command not found
bash: line 9: jhf: command not found
bash: line 10: mjw: command not found
bash: line 11: czw: command not found
bash: line 12: txh: command not found
bash: line 13: krn: command not found
bash: line 14: sct: command not found
bash: line 15: jad: command not found

我希望它只输出:

drs
tep
ldo
tep
txw
tep
jfp
mys
jhf
mjw
czw
txh
krn
sct
jad

我有办法做到这一点吗？请记住，我还有多个其他三个字母组合，所有字母都是字母表中的字母。

Answer 1

为什么要使用正则表达式？你让你的生活过于复杂了:

def three_letters_excluding_not(text)
    text
      .split(/\W+/)
      .select{|w| w.length == 3}
      .reject{|w| w=="not}
end

简短、简单、可读，享受 Ruby 的强大功能。