Select/clean email strings using regex

Question

I would like to validate (select) db with the appropriate email format.

SO related post here

Example: Selecting the appropriate format:

example.data <- c("[email protected]","mailto:[email protected]","@tint.com",
"tint@","tint.tint.com",
"orange.com","orange@orange","[email protected]",
"e-mail: [email protected]","mailto:%[email protected]")

desired.out <- c("[email protected]","mailto:[email protected]","[email protected]",
    "[email protected]","[email protected]")

Would someone share working solution? Thanks.

I posted a solution but this is solely based on the pattern showed in the example — akrun, May 21 '15 at 11:29
orange@orange is a valid email address syntax. Otherwise you were not able to write e.g. master@localhost. Here's a good discussion of the topic http://www.regular-expressions.info/email.html — Peter Paul Kiefer, May 21 '15 at 11:37
@Peter; yes indeed, thanks for that! I'm going to have a look on that. — Maximilian, May 21 '15 at 11:45
@Maximilian There are also solutions provided there. I forgott ;-) — Peter Paul Kiefer, May 21 '15 at 11:47
I think in the example.data you have `e-mail: [email protected]"` and the desired output is different — akrun, May 21 '15 at 11:47
What I meant is that if you are selecting a substring of `email: k-supra...` then why did you omit `"mailto:[email protected]"` — akrun, May 21 '15 at 11:56
@akrun: yes you are right. I thought about selecting+cleaning :) In case like: `"mailto:%[email protected]"` is going to be difficult, since not sure where to cut it off 20k-... or k-...., anyway, selecting with `@` would be great for now on. Thank you! — Maximilian, May 21 '15 at 12:01
`grep('^[^@]+@[^@]+\\.[^.]+$', example.data, value=TRUE)` gets the elements in the desired output — akrun, May 21 '15 at 12:03
I updated with a `sub` step to clean the email. Check if that helps — akrun, May 21 '15 at 12:16

akrun · Accepted Answer · 2015-05-21T12:15:50.507

2

You can try

 v1 <- grep('^[^@]+@[^@]+\\.[^.]+$', example.data, value=TRUE)
 v1
 #[1] "[email protected]"                 "mailto:[email protected]"         
 #[3] "[email protected]"             "e-mail: [email protected]"  
 #[5] "mailto:%[email protected]"

To clean the strings, may be

 sub('^[^:]+:( |%\\d+)?', '', v1)
 #[1] "[email protected]"       "[email protected]"       "[email protected]"  
 #[4] "[email protected]" "[email protected]"


 grep('^[^@]+@[^@]+\\.[^.]+$', '[email protected]', value=TRUE)
 #[1] "[email protected]"

edited May 21 '15 at 12:15

answered May 21 '15 at 11:28

akrun

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This wouldn't capture cases like "[email protected]" because of the "." preceeding the @. – talat May 21 '15 at 11:32
1

@Maximillian, You could change it depending upon what characters will be present on either side of `@` and after `.` – akrun May 21 '15 at 11:33
2

`grep('^[^@:]+@[^@]+\\.[^.]+$', example.data, value=TRUE)` may be an alternative – akrun May 21 '15 at 11:35
@akrun: yes the last suggestion is way better, capturing `"[email protected]"`, which is a must. Thanks. – Maximilian May 21 '15 at 11:37
@akrun: I have slightly edited my question, basically extending by two more cases? Would you be so kind and have a look? Thanks! – Maximilian May 21 '15 at 11:44

Select/clean email strings using regex

1 Answers1