正则表达式匹配马虎分数/混合数字

Question

我有一系列包含混合数字的文本(即:整个部分和小数部分)。问题是文本充满了人为编码的草率:

整个部分可能存在也可能不存在(例如:“10”)

小数部分可能存在也可能不存在(例如:“1/3”)

这两个部分可以用空格和/或连字符分隔(例如:“10 1/3”、“10-1/3”、“10 - 1/3”)。

分数本身在数字和斜杠之间可能有也可能没有空格(例如:“1/3”、“1/3”、“1/3”)。

小数后面可能还有其他文字需要忽略

我需要一个可以解析这些元素的正则表达式，以便我可以从这个困惑中创建一个适当的数字。

Answer 1

这是一个正则表达式，它将处理我可以抛出的所有数据:

(\d++(?! */))? *-? *(?:(\d+) */ *(\d+))?.*$

这会将数字分为以下几组:

带号的整个部分，如果存在

分子，如果一个分数退出

分母，如果存在一个分数

此外，这里是 RegexBuddy 对元素的解释(在构建它时对我有很大帮助):

Match the regular expression below and capture its match into backreference number 1 «(\d++(?! */))?»
   Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
   Match a single digit 0..9 «\d++»
      Between one and unlimited times, as many times as possible, without giving back (possessive) «++»
   Assert that it is impossible to match the regex below starting at this position (negative lookahead) «(?! */)»
      Match the character “ ” literally « *»
         Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
      Match the character “/” literally «/»
Match the character “ ” literally « *»
   Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
Match the character “-” literally «-?»
   Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
Match the character “ ” literally « *»
   Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
Match the regular expression below «(?:(\d+) */ *(\d+))?»
   Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
   Match the regular expression below and capture its match into backreference number 2 «(\d+)»
      Match a single digit 0..9 «\d+»
         Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
   Match the character “ ” literally « *»
      Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
   Match the character “/” literally «/»
   Match the character “ ” literally « *»
      Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
   Match the regular expression below and capture its match into backreference number 3 «(\d+)»
      Match a single digit 0..9 «\d+»
         Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match any single character that is not a line break character «.*»
   Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
Assert position at the end of the string (or before the line break at the end of the string, if any) «$»