How to search string members of a list in another string in Python 2

Question

I have a string, let's say an email From field:

str1 = "Name <[email protected]>"

(or perhaps with another format, the thing is that inside of str an email address is found...)

And I have a list of addresses:

lst = ["[email protected]", "[email protected]", "[email protected]", "[email protected]"]

What is the most pythonic way to search if the part of str with the email address is one of the members on lst ?

In the example, the email part of str1 is part of lst, but for:

str2 = "Another email [email protected]"

it is not...

Also,

str3 = "Example [email protected]"

would match because [email protected] is in the list, no matter there's no '<' '>' surrounding the email addres...

Marco Mariani · Accepted Answer · 2012-03-14T23:55:10.320

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from http://love-python.blogspot.com/2008/04/python-code-to-scrape-email-address.html

>>> email_pattern = re.compile("[-a-zA-Z0-9._]+@[-a-zA-Z0-9_]+.[a-zA-Z0-9_.]+")
>>> str = "Name <[email protected]>"
>>> str2 = "Another email [email protected]"
>>> lst = ["[email protected]", "[email protected]", "[email protected]", "[email protected]"]
>>> import re
>>> set(re.findall(email_pattern, str)).intersection(lst)
set(['[email protected]'])
>>> set(re.findall(email_pattern, str2)).intersection(lst)
set([])

edited Mar 14 '12 at 23:55

answered Mar 14 '12 at 23:39

Marco Mariani

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well, before your edition, I thought that was what I need... I mean, without the '<%s>' % l, but just l ... As you noticed, "Name [email protected]" won't match, which I need. But why is this a problem with "[email protected]"? – Javier Novoa C. Mar 14 '12 at 23:46
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"[email protected]" contains "[email protected]", but they are distinct addresses and should not match. – Marco Mariani Mar 14 '12 at 23:49
wait, I edited my post, seems that I didn't explained it better. the '<>' surrounding the email address shouldn't be necessary in my case... – Javier Novoa C. Mar 14 '12 at 23:52
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how about this version? keep in mind that perfectly matching email addresses with regexp can get hideously complex. – Marco Mariani Mar 14 '12 at 23:56
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"hideously complex" indeed. See http://ex-parrot.com/~pdw/Mail-RFC822-Address.html for example, and note that the spec allows things that have to be preprocessed and otherwise can't be parsed by a proper regex at all. – Karl Knechtel Mar 15 '12 at 00:30

Rik Poggi · Answer 2 · 2012-03-14T23:59:04.557

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Usually regex are not considered pythonic, but this seems a task made exactly for them.

So I would use them, extract the email adress and check if it's in the list:

>>> re.search(r'<(.*)>', "Name <[email protected]>").group(1) in lst
True

"pythonic" isn't a word to throw there that will solve any problem, one should consider all the available options and choose the best one.

Edit: If the format of your field isn't standard, no problem: you just need a better regex that will match the email. (I'm sure there are a ton of examples out there, I'm not going to google it for you).

But that doesn't mean that you shouldn't use regex for this kind of task.

edited Mar 14 '12 at 23:59

answered Mar 14 '12 at 23:46

Rik Poggi

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@JavierNovoaC.: It doesn't matter if the email adress is not surrounded by `<>`, I just show you an simple example with a basic regex. You can use a different regex to extract the email adress. I really don't see the problem. – Rik Poggi Mar 15 '12 at 00:01
thanks, I'll search for it. I was looking for a pythonic solution, thinking on the context of my problem, but that thing you mention is a good advice... – Javier Novoa C. Mar 15 '12 at 00:02

score 1 · Answer 3 · answered Mar 15 '12 at 03:52

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I don't know if this is pythonic:

return str1.split('<')[1].split('>')[0] in lst

answered Mar 15 '12 at 03:52

lllluuukke

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How to search string members of a list in another string in Python 2

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