如何用C#正则表达式替换转录文本中的重复词（含逗号分隔）

1. 单个重复单词的处理 #

针对带逗号或空格分隔的重复单词（如"I, I, I"、"I I"），可以用正则结合循环替换解决多次重复的问题：

正则表达式 #

var wordRegex = new Regex(@"\b(\w+)(?:,\s*)?\s+\1\b", RegexOptions.IgnoreCase);

• \b(\w+)：匹配单个单词并捕获为分组1
• (?:,\s*)?：匹配可选的逗号加任意空格（非捕获分组，不影响替换结果）
• \s+\1\b：匹配一个或多个空格后重复的分组1单词，确保单词边界避免部分匹配

C# 实现代码 #

string input = "I, I, I am really wanting to go, but I I am not, am not able to do it.";
string result = input;
var wordRegex = new Regex(@"\b(\w+)(?:,\s*)?\s+\1\b", RegexOptions.IgnoreCase);

// 循环替换直到无匹配项，处理三次及以上重复的情况
while (wordRegex.IsMatch(result))
{
    result = wordRegex.Replace(result, "$1");
}

处理后结果：I am really wanting to go, but I am not able to do it.

2. 重复短语的处理 #

针对"you know, you know you know"这类短语重复，优先推荐针对特定短语处理（避免通用正则误匹配）：

特定短语处理示例 #

string inputPhrase = "you know, you know you know what I mean";
string resultPhrase = inputPhrase;
var phraseRegex = new Regex(@"\b(you know)(?:,\s*)?\s+\1\b", RegexOptions.IgnoreCase);

while (phraseRegex.IsMatch(resultPhrase))
{
    resultPhrase = phraseRegex.Replace(resultPhrase, "$1");
}

处理后结果：you know what I mean

通用短语匹配（谨慎使用） #

如果需要处理任意短语重复，可使用以下正则（可能匹配语义重复的非冗余内容，需测试调整）：

var generalPhraseRegex = new Regex(@"\b([\w\s]+?)(?:,\s*)?\s+\1\b", RegexOptions.IgnoreCase);

3. 组合处理流程 #

可以先处理单词重复，再处理短语重复，覆盖更多场景：

string originalText = "I, I, I am really wanting to go, but I I am not, am not able to do it. you know, you know you know";
string processedText = originalText;

// 处理单词重复
var wordRegex = new Regex(@"\b(\w+)(?:,\s*)?\s+\1\b", RegexOptions.IgnoreCase);
while (wordRegex.IsMatch(processedText))
{
    processedText = wordRegex.Replace(processedText, "$1");
}

// 处理特定短语重复
var phraseRegex = new Regex(@"\b(you know)(?:,\s*)?\s+\1\b", RegexOptions.IgnoreCase);
while (phraseRegex.IsMatch(processedText))
{
    processedText = phraseRegex.Replace(processedText, "$1");
}

最终结果：I am really wanting to go, but I am not able to do it. you know

内容的提问来源于stack exchange，提问作者Andrew Harbert