Python3, re.match with list

Question

I read this : https://stackoverflow.com/a/17090205/6426449

And I made a list that cannot be used on username in django.

list : FORBIDDEN_USERNAME_LIST = ['admin', 'master', 'owner']

So I made a code like this :

views.py

def username_choice(request):

    if request.method == "POST":
        username = request.POST['username']    
        for item in forbidden.FORBIDDEN_USERNAME_LIST:
            match = re.search("r'\b"+item+"\b'", username)
            if match:
                return JsonResponse({'result': item + 'banned username'})

But It seems that it does not work.

Maybe I think, match = re.search("r'\b"+item+"\b'", username) Here is problem.

How can I fix that?

how are you entering the username from the frontend? – Exprator Dec 27 '17 at 09:42 — Exprator, Dec 27 '17 at 09:42
you better check this thing in the form validation. – babygame0ver Dec 27 '17 at 10:38 — babygame0ver, Dec 27 '17 at 10:38

score 2 · Accepted Answer · answered Dec 27 '17 at 11:31

2

You could simply use in:

forbidden = ['admin', 'master', 'owner']
username = request.POST['username']
match = [nm for nm in forbidden if nm in username]
if match:
    # part of the username is in the forbidden list.

Example in IPython:

In [1]: forbidden = ['admin', 'master', 'owner']

In [2]: username = 'owner123'

In [3]: match = [nm for nm in forbidden if nm in username]

In [4]: match
Out[4]: ['owner']

answered Dec 27 '17 at 11:31

Roland Smith

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I like that this approach doesn't use regexes. – gonczor Dec 27 '17 at 11:34

Exprator · Answer 2 · 2017-12-27T10:32:56.450

1

def username_choice(request):

    if request.method == "POST":
        username = request.POST['username']    
        for item in forbidden.FORBIDDEN_USERNAME_LIST:
          if re.search(r'\b'+str(item)+'\\b', username, re.I):
              return JsonResponse({'result': item + 'banned username'})

edited Dec 27 '17 at 10:32

answered Dec 27 '17 at 09:43

Exprator

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Thanks Exprator, but what if `username = admin123` ? I want to also ban all username with any of forbidden_username_list. – touchingtwist Dec 27 '17 at 09:49

score 1 · Answer 3 · edited Dec 27 '17 at 13:23

1

Just use this statement:

match = re.search(r'[%s]+' % item, username, re.I)

instead of this:

match = re.search("r'\b"+item+"\b'", username)

edited Dec 27 '17 at 13:23

Dmitry

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answered Dec 27 '17 at 12:04

Veera Balla Deva

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Python3, re.match with list

3 Answers3

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