python - 用于从电子邮件主题中删除 "FWD"、 "RE"等的正则表达式/代码

Question

给定一个电子邮件主题行，我想清理它，摆脱“Re:”、“Fwd”和其他垃圾。因此，例如，“[Fwd] Re: Jack and Jill's Wedding”应该变成“Jack and Jill's Wedding”。

以前肯定有人这样做过，所以我希望你能指点我经过战斗测试的正则表达式或代码。

以下是一些需要清理的示例，可在 this page 上找到.该页面上的正则表达式工作得很好，但并不完全。

Fwd : Re : Re: Many
Re : Re: Many
Re  : : Re: Many
Re:: Many
Re; Many
: noah - should not match anything
RE--
RE: : Presidential Ballots for Florida
[RE: (no subject)]
Request - should not match anything
this is the subject (fwd)
Re: [Fwd: ] Blonde Joke
Re: [Fwd: [Fwd: FW: Policy]]
Re: Fwd: [Fwd: FW: "Drink Plenty of Water"]
FW: FW: (fwd) FW:  Warning from XYZ...
FW: (Fwd) (Fwd) 
Fwd: [Fwd: [Fwd: Big, Bad Surf Moving]]
FW: [Fwd: Fw: drawing by a school age child in PA (fwd)]
Re: Fwd

Answer 1

试试这个(替换为''):

/([\[\(] *)?(RE|FWD?) *([-:;)\]][ :;\])-]*|$)|\]+ *$/igm

(如果您将每个主题作为其自己的字符串，那么您不需要 m 修饰符；这只是为了让 $ 匹配行尾，而不是只是字符串的结尾，用于多行字符串输入)。

查看实际效果 here .

正则解释:

([\[\(] *)?            # starting [ or (, followed by optional spaces
(RE|FWD?) *            # RE or FW or FWD, followed by optional spaces
([-:;)\]][ :;\])-]*|$) # only count it as a Re or FWD if it is followed by 
                       # : or - or ; or ] or ) or end of line
                       # (and after that you can have more of these symbols with
                       #  spaces in between)
|                      # OR
\]+ *$                 # match any trailing \] at end of line 
                       # (we assume the brackets () occur around a whole Re/Fwd
                       #  but the square brackets [] occur around the whole 
                       #  subject line)

旗帜。

i:不区分大小写。

g:全局匹配(匹配你能找到的所有Re/Fwd)。

m:让正则表达式中的“$”匹配多行输入的行尾，而不仅仅是字符串的结尾(仅当您将所有输入主题同时输入正则表达式时才相关. 如果您每次输入一个主题，那么您可以将其删除，因为行尾是字符串的结尾)。