import osimport sysimport hashlibfrom django.conf import settingsDEBUG = os.environ.get(‘DEBUG‘, ‘on‘) == ‘on‘SECRET_KEY = os.environ.get(‘SECRET_KEY‘, ‘%jv_4#hoaqwig2gu!eg#^ozptd*a@88u(aasv7z!7xt^5(*i&k‘)ALLOWED_HOSTS = os.environ.get(‘ALLOWED_HOSTS‘, ‘localhost‘).split(‘,‘)BASE_DIR = os.path.dirname(__file__)settings.configure(    DEBUG=DEBUG,    TEMPLATE_DEBUG = True,    SECRET_KEY=SECRET_KEY,    ALLOWED_HOSTS=ALLOWED_HOSTS,    ROOT_URLCONF=__name__,    MIDDLEWARE_CLASSES=(        ‘django.middleware.common.CommonMiddleware‘,        ‘django.middleware.csrf.CsrfViewMiddleware‘,        ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘,    ),    INSTALLED_APPS=(        ‘django.contrib.staticfiles‘,    ),    TEMPLATES = [        {            ‘BACKEND‘: ‘django.template.backends.django.DjangoTemplates‘,            ‘DIRS‘: [                os.path.join(BASE_DIR,‘templates‘).replace(‘\\‘, ‘/‘),            ],            ‘APP_DIRS‘: True,        }    ],    STATICFILES_DIRS=(        os.path.join(BASE_DIR, ‘static‘),    ),    STATIC_URL=‘/static/‘,)from django import formsfrom django.conf.urls import urlfrom django.core.urlresolvers import reversefrom django.core.cache import cachefrom django.core.wsgi import get_wsgi_applicationfrom django.http import HttpResponse, HttpResponseBadRequestfrom django.shortcuts import renderfrom django.views.decorators.http import etagfrom io import BytesIOfrom PIL import Image, ImageDrawclass ImageForm(forms.Form):    height = forms.IntegerField(min_value=http://www.mamicode.com/1, max_value=2000)    width = forms.IntegerField(min_value=http://www.mamicode.com/1, max_value=2000)    def generate(self, image_format=‘PNG‘):        """Generate an image of the given type and return as raw bytes."""        height = self.cleaned_data[‘height‘]        width = self.cleaned_data[‘width‘]        key = ‘{}.{}.{}‘.format(width, height, image_format)        content = cache.get(key)        if content is None:            image = Image.new(‘RGB‘, (width, height))            draw = ImageDraw.Draw(image)            text = ‘{} X {} demo‘.format(width, height)            textwidth, textheight = draw.textsize(text)            if textwidth < width and textheight < height:                texttop = (height - textheight) // 2                textleft = (width - textwidth) // 2                draw.text((textleft, texttop), text, fill=(255, 155, 5))            content = BytesIO()            image.save(content, image_format)            content.seek(0)            cache.set(key, content, 60 * 60)        return contentdef generate_etag(request, width, height):    content = ‘Placeholder: {0} x {1}‘.format(width, height)    return hashlib.sha1(content.encode(‘utf-8‘)).hexdigest()@etag(generate_etag)def placeholder(request, width, height):    form = ImageForm({‘height‘: height, ‘width‘: width})    if form.is_valid():        image = form.generate()        return HttpResponse(image, content_type=‘image/png‘)    else:        return HttpResponseBadRequest("Invalid Image Request")def index(request):    example = reverse(‘placeholder‘, kwargs={‘width‘: 500, ‘height‘: 500})    print example, ‘#####################‘    context = {        ‘example‘: request.build_absolute_uri(example)    }    print context, ‘@@@@@@@@@@@@@@@@@@@@@@@‘    return render(request, ‘home.html‘, context)urlpatterns = (    url(r‘^image/(?P<width>[0-9]+)x(?P<height>[0-9]+)/$‘, placeholder, name=‘placeholder‘),    url(r‘^$‘, index, name=‘homepage‘),)application = get_wsgi_application()if __name__ == "__main__":    from django.core.management import execute_from_command_line    execute_from_command_line(sys.argv)