How to validate an Email address in Django? [duplicate]

Question

I have written a function for adding emails to newsletter base. Until I've added checking validity of sent email it was working flawlessly. Now each time I'm getting "Wrong email" in return. Can anybody see any errors here ? The regex used is :

\b[\w\.-]+@[\w\.-]+\.\w{2,4}\b and it is 100% valid (http://gskinner.com/RegExr/), but I may be using it wrong, or it may be some logic error :

def newsletter_add(request):
    if request.method == "POST":   
        try:
            e = NewsletterEmails.objects.get(email = request.POST['email'])
            message = _(u"Email is already added.")
            type = "error"
        except NewsletterEmails.DoesNotExist:
            if validateEmail(request.POST['email']):
                try:
                    e = NewsletterEmails(email = request.POST['email'])
                except DoesNotExist:
                    pass
                message = _(u"Email added.")
                type = "success"
                e.save()
            else:
                message = _(u"Wrong email")
                type = "error"

import re

def validateEmail(email):
    if len(email) > 6:
        if re.match('\b[\w\.-]+@[\w\.-]+\.\w{2,4}\b', email) != None:
            return 1
    return 0

100% valid? Won't match [email protected], won't match [email protected], and tons more. — Kos
– Kos, Commented Dec 23, 2013 at 10:37
Actually @Kos @Zenadix...both of you are wrong with regards to the \b[\w\.-]+@[\w\.-]+\.\w{2,4}\b regex. I just tested it and it does the opposite of what both of you say. — theQuestionMan
– theQuestionMan, Commented Feb 25, 2021 at 3:03

o3bvv · Accepted Answer · 2019-09-16 20:37:34Z

241

from django.core.exceptions import ValidationError
from django.core.validators import validate_email

value = "[email protected]"

try:
    validate_email(value)
except ValidationError as e:
    print("bad email, details:", e)
else:
    print("good email")

edited Sep 16, 2019 at 20:37

answered Oct 7, 2013 at 10:29

o3bvv

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6 Comments

keithhackbarth Over a year ago

This solution wasn't available back when the questions was originally asked, but is definitely the best answer.

Jay Modi Over a year ago

And still the best answer in 2017..! Forward to 2018..! This should be definitely accepted answer as per the current stream.

Shubham Patel Over a year ago

Best answer in 2018 and 2019. Forward to 2020..

Daniel Benedykt Over a year ago

Best answer in 2022 ... Forward to 2023

kta Over a year ago

Apart from this, good to know that we could also use Else statement with Try..Catch. Cheers.

|

Matthew Hegarty · Accepted Answer · 2021-10-28 07:00:23Z

172

UPDATE 2017: the code below is 7 years old and was since modified, fixed and expanded. For anyone wishing to do this now, the correct code lives around here.

Here is part of django.core.validators you may find interesting :)

class EmailValidator(RegexValidator):

    def __call__(self, value):
        try:
            super(EmailValidator, self).__call__(value)
        except ValidationError, e:
            # Trivial case failed. Try for possible IDN domain-part
            if value and u'@' in value:
                parts = value.split(u'@')
                domain_part = parts[-1]
                try:
                    parts[-1] = parts[-1].encode('idna')
                except UnicodeError:
                    raise e
                super(EmailValidator, self).__call__(u'@'.join(parts))
            else:
                raise

email_re = re.compile(
    r"(^[-!#$%&'*+/=?^_`{}|~0-9A-Z]+(\.[-!#$%&'*+/=?^_`{}|~0-9A-Z]+)*"  # dot-atom
    r'|^"([\001-\010\013\014\016-\037!#-\[\]-\177]|\\[\001-011\013\014\016-\177])*"' # quoted-string
    r')@(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+[A-Z]{2,6}\.?$', re.IGNORECASE)  # domain
validate_email = EmailValidator(email_re, _(u'Enter a valid e-mail address.'), 'invalid')

so if you don't want to use forms and form fields, you can import email_re and use it in your function, or even better - import validate_email and use it, catching possible ValidationError.

def validateEmail( email ):
    from django.core.validators import validate_email
    from django.core.exceptions import ValidationError
    try:
        validate_email( email )
        return True
    except ValidationError:
        return False

And here is Mail::RFC822::Address regexp used in PERL, if you really need to be that paranoid.

edited Oct 28, 2021 at 7:00

Matthew Hegarty

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answered Jul 10, 2010 at 6:32

cji

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5 Comments

Yogev Shelly Over a year ago

Thanks, had an import with email_re (that's the snippet across the web) but your second code block did the trick

jptsetung Over a year ago

This is not valid anymore with the upcoming new top level domain extensions (more than 6 chars for the extensions I think) mashable.com/2011/06/21/icann-top-level-domains-change

kalefranz Over a year ago

I believe there may be a bug in the email_re expression. Specifically in the quoted string line, I'm guessing the intent is that \001-011 should actually be \001-\011. Any thoughts?

kalefranz Over a year ago

Indeed, there is a typo in the code above. Source on github has since been fixed: github.com/django/django/blob/master/django/core/validators.py Fair warning to those copying and pasting that regex.

Divij Sehgal Over a year ago

The update part is the best part. :D

Amin Mir · Accepted Answer · 2021-03-19 16:58:40Z

60

Ick, no, please, don't try to validate email addresses yourself. It's one of those things people never get right.

Your safest option, since you're already using Django, is to just take advantage of its form validation for email. Per the docs:

>>> from django import forms
>>> f = forms.EmailField()
>>> f.clean('[email protected]')
u'[email protected]'
>>> f.clean(u'[email protected]')
u'[email protected]'
>>> f.clean('invalid e-mail address')
...
ValidationError: [u'Enter a valid e-mail address.']

edited Mar 19, 2021 at 16:58

Amin Mir

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answered Jul 10, 2010 at 3:27

Nicholas Knight

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3 Comments

Imre Kelényi Over a year ago

Here is a tiny Python module based on this method. Just use isEmailAddressValid(address) to perform the validation.

Luis Artola Over a year ago

Since the question is about Django, this is the best answer. +1 for encouraging code reuse and simplicity.

Chidananda Nayak Over a year ago

simple is better than complex , very good explanation

msw · Accepted Answer · 2010-07-10 03:45:46Z

7

You got it wrong, but it is a task that you can't do anyway. There is one and only one way to know if an RFC 2822 address is valid, and that is to send mail to it and get a response. Doing anything else doesn't improve the information content of your datum by even a fractional bit.

You also screw the human factor and acceptance property, for when you give validateEmail my address of

[email protected]

and you tell me I've made an error, I tell your application goodbye.

answered Jul 10, 2010 at 3:45

msw

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3 Comments

muntu Over a year ago

fortunately this regex is not mine :) So you're also for the normal EmailField method ?

msw Over a year ago

I don't speak django, but the argument applies to any attempt to syntactically validate an address. code.djangoproject.com/ticket/3344 Looks like not even EmailField may be up to the task (but I didn't look real hard)

cji Over a year ago

that particular ticket is marked as fixed since 07/04/07, and bug there was in unicode handling of translated error message. I think that using Django validators is relatively safe now.

Himanshu Poddar · Accepted Answer · 2018-12-25 12:24:43Z

3

I can see many answers here are based on django framework of python. But for verifying an email address why to install such an heavy software. We have the Validate_email package for Python that check if an email is valid, properly formatted and really exists. Its a light weight package (size < 1MB).

INSTALLATION :

pip install validate_email

Basic usage:

Checks whether email is in proper format.

from validate_email import validate_email
is_valid = validate_email('[email protected]')

To check the domain mx and verify email exists you can install the pyDNS package along with validate_email.

Verify email exists :

from validate_email import validate_email
is_valid = validate_email('[email protected]',verify=True)

Returns True if the email exist in real world else False.

answered Dec 25, 2018 at 12:24

Himanshu Poddar

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1 Comment

Rohit Kumar Over a year ago

I believe this does not work for python 3 and only for python 2.

Kent Astudillo · Accepted Answer · 2013-10-07 07:01:31Z

0

Change your code from this:

re.match('\b[\w.-]+@[\w.-]+.\w{2,4}\b', email)

to this:

re.match(r'\b[\w.-]+@[\w.-]+.\w{2,4}\b', email)

works fine with me.

edited Oct 7, 2013 at 7:01

answered Oct 7, 2013 at 6:53

Kent Astudillo

11 bronze badge

Comments

Zenadix · Accepted Answer · 2014-09-25 21:20:05Z

0

This regex will validate an email address with reasonable accuracy.

\w[\w\.-]*@\w[\w\.-]+\.\w+

It allows alphanumeric characters, _, . and -.

edited Sep 25, 2014 at 21:20

answered Sep 25, 2014 at 20:54

Zenadix

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