如何从 R 中的字符串中删除这些元素 [关闭]答案

【问题标题】：How to remove these elements from my string in R [closed]如何从 R 中的字符串中删除这些元素 [关闭]
【发布时间】：2023-03-24 03:43:02
【问题描述】：

我的一个专栏包含以下字符串：

    259333154-Carat Programmatic»FCO»O»EV3»D&B - FCO Prospects ABM DDD 2020 D&B ABM ENDING 1/31/2020»NA+728 x 90»IN»UNV»TP»PM»dCPM»NAT»BTP»RON»NA»DB»N/A»ENG»M»P159WXZ
    238114259-Carat Programmatic»CPO XT5»O»EV2»END DATE 2/28/19 Google Custom Intent - XT5 CPO Google Custom Intent Audience/In Market Audience»NA+160 x 600»IN»DSK»TP»PM»CPM»NAT»BTS»RON»NA»DB»N/A»ENG»M»PX5LV6
    251368220-Carat Programmatic»XT6»O»EV1»END DATE 9/30/19 2019   Cadillac SMRT Always On - CRM - SMRT Segment XT6 Desktop Display»NA+160 x 600»IN»DSK»TP»PM»CPM»NAT»PRS»RON»NA»DB»N/A»ENG»M»P12LQG3
    235105211-Ebay»Silverado 1500»M»CON»ended   3/20 - ROS - eBay Run of Motors Desktop»NA+300 x 250»IN»DSK»TP»PM»CPM»NAT»SCR»ROS»NA»DB»N/A»ENG»M»PW79JH
    234990143-Carat Programmatic»XT4»O»EV2»Endemic - Loyalist|Edmunds&Oracle|N/A|Vehicle|N/A 2»NA+300 x 250»IN»MOB»TP»PM»CPM»NAT»BTO»RON»IMW»DB»N/A»ENG»M»PW7NSN

我的任务是从字符串中删除以下内容：

日期（例如1/31/2020、3/20）
像Ending、ENDING、END、end、End、END DATE 这样的字符串，但不是像最后一个那样包含 endemic 的字符串的“结尾”
双空格，例如" "

我真的很难接受。我正在使用如下几行代码来执行一些操作，但不知道如何更简洁完整地执行此操作：

dat = gsub("2017|2018|2019|2020", "" ,dat)
dat = gsub("»»", "»", dat)
dat = gsub("END ", "", dat)
dat = gsub("end ", "", dat)
dat = gsub("Ended ", "", dat)
dat = gsub("ENDED ", "", dat)
dat = gsub("DATE|date|Date", "", dat)

非常感谢您的帮助！

【问题讨论】：

标签： r string replace str-replace gsub

【解决方案1】：

检查以下内容：

\b(?:0?[1-9]|1[012])(?:[-/.](?:0?[1-9]|[12][0-9]|3[01]))?[-/.](?:19|20)?\d\d\b 应该处理“日期（例如 1/31/2020、3/20）”的情况
(?i)\bEnd(?: DATE|(?:ing)?)\b 应该处理“像“Ending”、“ENDING”、“END”、“end”、“End”、“END DATE”这样的“字符串”，而不是像“endemic”这样的字符串中的“end”最后一个”案例
([\s»]){2,} 应该处理“双空格，例如”“”的情况。

结合所有：

gsub("\\b(?:End(?:\\s+DATE|(?:ing)?)|(?:0?[1-9]|1[012])(?:[-/.](?:0?[1-9]|[12][0-9]|3[01]))?[-/.](?:19|20)?\\d\\d)\\b|([\\s»]){2,}", "\\1", x, perl=TRUE, ignore.case=TRUE)

见proof。

说明

--------------------------------------------------------------------------------
  \b                       the boundary between a word char (\w) and
                           something that is not a word char
--------------------------------------------------------------------------------
  (?:                      group, but do not capture:
--------------------------------------------------------------------------------
    End                      'End'
--------------------------------------------------------------------------------
    (?:                      group, but do not capture:
--------------------------------------------------------------------------------
       DATE                    ' DATE'
--------------------------------------------------------------------------------
     |                        OR
--------------------------------------------------------------------------------
      (?:                      group, but do not capture (optional
                               (matching the most amount possible)):
--------------------------------------------------------------------------------
        ing                      'ing'
--------------------------------------------------------------------------------
      )?                       end of grouping
--------------------------------------------------------------------------------
    )                        end of grouping
--------------------------------------------------------------------------------
   |                        OR
--------------------------------------------------------------------------------
    (?:                      group, but do not capture:
--------------------------------------------------------------------------------
      0?                       '0' (optional (matching the most
                               amount possible))
--------------------------------------------------------------------------------
      [1-9]                    any character of: '1' to '9'
--------------------------------------------------------------------------------
     |                        OR
--------------------------------------------------------------------------------
      1                        '1'
--------------------------------------------------------------------------------
      [012]                    any character of: '0', '1', '2'
--------------------------------------------------------------------------------
    )                        end of grouping
--------------------------------------------------------------------------------
    (?:                      group, but do not capture (optional
                             (matching the most amount possible)):
--------------------------------------------------------------------------------
      [-/.]                    any character of: '-', '/', '.'
--------------------------------------------------------------------------------
      (?:                      group, but do not capture:
--------------------------------------------------------------------------------
        0?                       '0' (optional (matching the most
                                 amount possible))
--------------------------------------------------------------------------------
        [1-9]                    any character of: '1' to '9'
--------------------------------------------------------------------------------
       |                        OR
--------------------------------------------------------------------------------
        [12]                     any character of: '1', '2'
--------------------------------------------------------------------------------
        [0-9]                    any character of: '0' to '9'
--------------------------------------------------------------------------------
       |                        OR
--------------------------------------------------------------------------------
        3                        '3'
--------------------------------------------------------------------------------
        [01]                     any character of: '0', '1'
--------------------------------------------------------------------------------
      )                        end of grouping
--------------------------------------------------------------------------------
    )?                       end of grouping
--------------------------------------------------------------------------------
    [-/.]                    any character of: '-', '/', '.'
--------------------------------------------------------------------------------
    (?:                      group, but do not capture (optional
                             (matching the most amount possible)):
--------------------------------------------------------------------------------
      19                       '19'
--------------------------------------------------------------------------------
     |                        OR
--------------------------------------------------------------------------------
      20                       '20'
--------------------------------------------------------------------------------
    )?                       end of grouping
--------------------------------------------------------------------------------
    \d                       digits (0-9)
--------------------------------------------------------------------------------
    \d                       digits (0-9)
--------------------------------------------------------------------------------
  )                        end of grouping
--------------------------------------------------------------------------------
  \b                       the boundary between a word char (\w) and
                           something that is not a word char
--------------------------------------------------------------------------------
 |                        OR
--------------------------------------------------------------------------------
  (                        group and capture to \1 (at least 2 times
                           (matching the most amount possible)):
--------------------------------------------------------------------------------
    [\s»]                    any character of: whitespace (\n, \r,
                             \t, \f, and " "), '»'
--------------------------------------------------------------------------------
  ){2,}                    end of \1 (NOTE: because you are using a
                           quantifier on this capture, only the LAST
                           repetition of the captured pattern will be
                           stored in \1)

【讨论】：

Ryszard 非常感谢！