oDesk Django Test Answers 2015

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1. Consider the following Python string representing a human readable date and time:
      dt = 'Jan 14 2009 11:00PM'

Which of the following code snippets will convert the above string to a Python Datetime object that is suitable for a django.models.DateField?
Answers:
• date_object = time.strptime(dt, '%b %d %Y %I:%M%p')
• date_object = datetime.strptime(dt, '%b %d %Y %I:%M%p')
• date_object = datetime.strptime(dt, '%B %D %Y %I:%M%p')
• date_object = time.strptime(dt, '%b %d %Y %I:%M%p')

2. Consider two Django QuerySets query_set_1 and query_set_2 from two different models.
Which of the following code snippets is the most performant when concatenating the two QuerySets into one list?
Answers:
• from itertools import chain result_list = list(chain(query_set_1,query_set_2))
• result_list = query_set_1 | query_set_2
• from django.db.models import Q result_list = Q(query_set_1) | Q(query_set_1)
• from itertools import chain result_list = chain(query_set_1, query_set_2)
3. Consider the following code snippet for a Django Model:

class Salary(models.Model):   
    amount = models.PositiveIntergerField(help_text='eg 8000')
    retired = models.BooleanField(help_text='True if above average')
    …........

Which of the following will correctly produce a QuerySet of all Salary objects where retired == True and amount != 7300?
Answers:
• results = Salary.objects.exclude(retired=true, amount__lt=7300).exclude(retired=true,amount__gt=7300)
• from django.db.models import Q results = Salary.filter(~Q(amount=7300),retired=True)
• results = Salary.objects.filtered(retired=True, amount__ne=7300)
• from django.db.models import Q results = Salary.filter(Q(amount=7300),retired=True)
4. Which of the following is false about the django.models.SlugField() model field?
Answers:
• It is used when performing a query, or as a part of a URL, since by default it ensures uniqueness.
• To create a slug based on another field automatically in the admin, prepopulated_fields has to be used.
• It can only contain letters, numbers, underscores or hyphens.
• Slugs can created in Django templates using the builtin filter, "django.template.defaultfilters.slugify", formatted as {{ some_text|slugify }}.
5. What does the django.core.context_processors.static() method do?
Answers:
• It takes a path and urljoins it with the static prefix STATIC_URL.
• It adds STATIC_URL to every template context rendered with RequestContext contexts.
• It populates a template variable with the static prefix STATIC_URL to be used as a variable or directly.
• None of these.
6. Which of the following statements is true about the django.template.RequestContext class?
Answers:
• It takes a Context object as its first argument.
• It takes an HttpRequest as its first argument.
• It does not automatically the context with variables.
• It can only be given one context processor.
7. Which of the following statements about database transactions in Django is false?
Answers:
• "atomic" blocks allows the creation of blocks of code within which the atomicity on the database is guaranteed.
• "atomic" blocks cannot be nested.
• "atomic" can be used as a decorator.
• "atomic" can be used as a context manager.
8. Which of the following gets called when a view raises an exception?
Answers:
• view_exception()
• process_exception()
• execution_exception()
• controller_exception()
9. What is the best way to extend the Django user model with extra custom fields in addition to the fields already provided?
Answers:
• Use a a proxy model based on django.contrib.auth.models.User.
• Subclass django.contrib.auth.models.AbstractUser and add the extra fields.
• Subclass django.contrib.auth.models.AbstractBaseUser and add the extra fields.
• Use a one-to-one relationship to a model containing the extra fields.
10. Which of the following statements are true about the ImageField class?
Answers:
• It inherits all attributes and methods from the FileField class.
• It validates that the uploaded object is a valid image.
• Its instances are created as varchar(200) columns in the database.
• It's default form widget is a ClearableFileInput.
11. What does the "with" template tag do?
Answers:
• It adds its argument to the value.
• It caches a complex under a simpler name.
• It filters the contents of the blog through one or more filters.
• None of these.
12. Which of the following statement is false about the django.http.HttpRequest.get_host() method ?
Answers:
• If DEBUG = False and ALLOWED_HOSTS= [] the method will raise SuspiciousOperation exception resulting in an HTTP Error 500 Internal server error.
• The method will fail when the host is behind multiple proxies, in this case one solution is to use middleware which will rewrite the proxy headers.
• This method is invoked if some code accesses the Host header from request.META, thus providing a security measure to prevent an attacker from poisoning caches and password reset emails with links to malicious hosts by submitting requests with a fake HTTP Host header.
• The method uses information from the HTTP_X_FORWARDED_HOST and HTTP_HOST headers, in that order, or a combination of SERVER_NAME and SERVER_PORT if the latter does not provide a value.
13. What is the default max_length value of a SlugField class in Django?
Answers:
• 50
• 100
• 25
• 150
14. Which of the following is a built-in BaseCommand subclass?
Answers:
• AppCommand
• HelperCommand
• HandlerCommand
• DBCommand
15. Which of the following statements is true about Django's default implementation of the authentication system?
Answers:
• Django stores passwords in plain text on the user model.
• It returns a UserAccount object is the password for a given username is authenticated.
• Permissions can only be set on a per type of object basis.
• django.contrib.auth will ensure that add, change and delete permissions are created for each Django model defined in an installed application.
16. Which of the following happens when process_exception() returns "None"?
Answers:
• The template response will be applied.
• The response middleware will be applied.
• The default exception handling will be applied.
• None of these.
17. Which of the following is not a predefined log level in Django?
Answers:
• DEBUG
• INFO
• WARNING
• FATAL
18. Which of the following classes uses an HTTP 304 status code?
Answers:
• HttpResponseNotModified
• HttpResponseRedirect
• HttpResponseForbidden
• HttpResponseServerError
19. Which of the following django.template.loader functions will take a list of template names and return the first template that exists?
Answers:
• find_one_template
• find_template
• get_template
• select_template
20. Which of the following is not a built-in Django template loader class?
Answers:
• file.Loader
• cached.Loader
• eggs.Loader
• app_directories.Loader