CSV import fails with error: '_csv.reader' object has no attribute 'next'

[candlerb]

Issue type: Bug

Python version: 3.5.2 (Ubuntu 16.04)
NetBox version: 2.0.6

To reproduce: go to Racks, Import Racks; paste the following and hit Submit

site,name,width,u_height
SomeSite,Foo,42,19

Result is a Server Error:

<class 'AttributeError'>

'_csv.reader' object has no attribute 'next'

Traceback received via E-mail:

    File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/exception.py" in inner
      41.             response = get_response(request)
    
    File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/base.py" in _get_response
      187.                 response = self.process_exception_by_middleware(e, request)
    
    File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/base.py" in _get_response
      185.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)
    
    File "/usr/local/lib/python3.5/dist-packages/django/views/generic/base.py" in view
      68.             return self.dispatch(request, *args, **kwargs)
    
    File "/usr/local/lib/python3.5/dist-packages/django/contrib/auth/mixins.py" in dispatch
      92.         return super(PermissionRequiredMixin, self).dispatch(request, *args, **kwargs)
    
    File "/usr/local/lib/python3.5/dist-packages/django/views/generic/base.py" in dispatch
      88.         return handler(request, *args, **kwargs)
    
    File "/opt/netbox/netbox/utilities/views.py" in post
      418.         if form.is_valid():
    
    File "/usr/local/lib/python3.5/dist-packages/django/forms/forms.py" in is_valid
      183.         return self.is_bound and not self.errors
    
    File "/usr/local/lib/python3.5/dist-packages/django/forms/forms.py" in errors
      175.             self.full_clean()
    
    File "/usr/local/lib/python3.5/dist-packages/django/forms/forms.py" in full_clean
      384.         self._clean_fields()
    
    File "/usr/local/lib/python3.5/dist-packages/django/forms/forms.py" in _clean_fields
      402.                     value = field.clean(value)
    
    File "/usr/local/lib/python3.5/dist-packages/django/forms/fields.py" in clean
      160.         value = self.to_python(value)
    
    File "/opt/netbox/netbox/utilities/forms.py" in to_python
      252.         headers = reader.next()
    
    Exception Type: AttributeError at /dcim/racks/import/
    Exception Value: '_csv.reader' object has no attribute 'next'

Judging by this post it appears to be a python 2/3 difference.

Applied following patch by hand:

--- /opt/netbox/netbox/utilities/forms.py.orig	2017-06-13 11:32:37.171228169 +0000
+++ /opt/netbox/netbox/utilities/forms.py	2017-06-14 12:47:19.245315962 +0000
@@ -249,7 +249,7 @@
         reader = csv.reader(value.splitlines())

         # Consume and valdiate the first line of CSV data as column headers
-        headers = reader.next()
+        headers = next(reader)
         for f in self.required_fields:
             if f not in headers:
                 raise forms.ValidationError('Required column header "{}" not found.'.format(f))

That appears to fix the problem.