Example of Proxy Model Metaprogramming Antipattern

views.py

from __future__ import unicode_literals

from django.shortcuts import render
from models import Visualization
from exceptions import IncompleteDataException, ConstantizeException
from .forms import VisualizationForm
from django.contrib.auth.decorators import login_required

import inspect, re

ClassRegex = re.compile("[a-zA-Z_][a-zA-Z0-9_]*")

def constantize(string):
  if not ClassRegex.match(string):
    raise ConstantizeException("`%s' contains illegal characters." % str(string))
  klass = eval(str(string))
  if not inspect.isclass(klass): raise ConstantizeException("`%s' does not refer to a class." % str(string))
  return klass

def snake_to_camel(word):
        import re
        return ''.join(x.capitalize() or '_' for x in word.split('_'))

@login_required
def transform(request):
    name = request.GET['script']

    if request.POST and request.FILES:
        form = VisualizaionForm(request.POST, request.FILES)

        if form.is_valid():
            input_file = request.FILES['file']
            image = None

            try:
                vizualization = constantize(snake_to_camel(name)).objects.get(pk=name)
                image = vizualization.from_data(name, input_file)

            except IncompleteDataException as e:
                return render(request, 'visualizations/form.html', {'error': e.message()})
                
        return render(request, 'visualizations/results.html', {'image': image})