urlpatterns list structure in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What does this urlpatterns list do?

Given this Django urlpatterns list, what URL path will trigger the home_view function?

Django

from django.urls import path
from .views import home_view

urlpatterns = [
    path('', home_view, name='home'),
    path('about/', lambda request: None, name='about'),
]

A The root URL path '/' triggers home_view

B No URL triggers home_view

C The URL path '/home/' triggers home_view

D The URL path '/about/' triggers home_view

💡 Hint

Look at the first path's first argument, it defines the URL pattern.

The empty string '' in path means the root URL. So '/' triggers home_view.

📝 Syntax

intermediate

Which urlpatterns list is syntactically correct?

Select the urlpatterns list that will NOT cause a syntax error in Django.

A urlpatterns = {path('home/', home_view), path('about/', about_view)}

B urlpatterns = [path('home/', home_view), path('about/', about_view)]

C urlpatterns = (path('home/', home_view), path('about/', about_view))

D urlpatterns = path('home/', home_view), path('about/', about_view)

💡 Hint

urlpatterns must be a list, not a set or tuple.

urlpatterns must be a list of path() calls. Option B uses a list [].

❓ state_output

advanced

How many URL patterns are in this urlpatterns list?

Count the number of URL patterns defined in this urlpatterns list.

Django

from django.urls import path, include

urlpatterns = [
    path('blog/', include('blog.urls')),
    path('shop/', include('shop.urls')),
    path('contact/', lambda request: None),
]

A 1

B 2

C 0

D 3

💡 Hint

Each path() call counts as one URL pattern.

There are three path() calls, so 3 URL patterns.

🔧 Debug

advanced

What error does this urlpatterns list cause?

Identify the error caused by this urlpatterns list.

Django

from django.urls import path

urlpatterns = [
    path('home/', home_view),
    path('about/', about_view),
    path('contact/', contact_view)
]

A TypeError because path() arguments are wrong

B No error, code runs fine

C NameError because home_view is not defined

D SyntaxError due to missing closing parenthesis

💡 Hint

Check the parentheses in the last path() call.

home_view, about_view, and contact_view are not defined, causing NameError.

🧠 Conceptual

expert

What is the effect of including another URLconf in urlpatterns?

In Django, what happens when you use path('blog/', include('blog.urls')) in urlpatterns?

A It adds all URL patterns from blog.urls under the 'blog/' path prefix

B It replaces the current urlpatterns with blog.urls

C It causes a runtime error because include() cannot be used in urlpatterns

D It creates a redirect from 'blog/' to blog.urls

💡 Hint

Think about how include() helps organize URLs.

include() adds all URL patterns from the specified module under the given prefix.

Practice

1. What is the main purpose of the urlpatterns list in a Django project?

easy

A. To store user data in the database

B. To connect website addresses (URLs) to the code that shows pages

C. To define the style of the website pages

D. To manage user login and authentication

Solution

1. Step 1: Understand the role of urlpatterns

   The urlpatterns list holds URL patterns that link URLs to views (code that shows pages).

2. Step 2: Compare with other options

   Storing user data uses models, defining styles uses templates/CSS, and managing authentication uses Django's auth system -- none of these are handled by urlpatterns.

3. Final Answer:

   To connect website addresses (URLs) to the code that shows pages -> Option B

4. Quick Check:

   urlpatterns connects URLs to views [OK]

Hint: Remember: urlpatterns links URLs to views [OK]

Common Mistakes:

• Thinking urlpatterns stores data
• Confusing urlpatterns with styling or authentication

2. Which of the following is the correct way to add a URL pattern to the urlpatterns list?

easy

A. link('home/', views.home_view)

B. url('home/', views.home_view)

C. path('home/', views.home_view)

D. route('home/', views.home_view)

Solution

1. Step 1: Identify the correct function for URL patterns

   Django uses path() to define URL patterns in urlpatterns.

2. Step 2: Check other options

   url() was used in older Django versions but is deprecated; route() and link() are not Django functions.

3. Final Answer:

   path('home/', views.home_view) -> Option C

4. Quick Check:

   Use path() for URL patterns [OK]

Hint: Use path() to add URLs in urlpatterns [OK]

Common Mistakes:

• Using deprecated url() instead of path()
• Trying non-existent functions like route() or link()

3. Given this urlpatterns list, what URL will show the about_view page?

from django.urls import path
from . import views

urlpatterns = [
    path('about/', views.about_view),
    path('contact/', views.contact_view),
]

medium

A. /contact/

B. /about-us/

C. /home/

D. /about/

Solution

1. Step 1: Read the urlpatterns entries

   The list has path('about/', views.about_view) which means the URL /about/ shows about_view.

2. Step 2: Match URLs to views

   /contact/ shows contact_view, others like /home/ or /about-us/ are not defined.

3. Final Answer:

   /about/ -> Option D

4. Quick Check:

   path('about/', views.about_view) means URL is /about/ [OK]

Hint: Match the string in path() to the URL [OK]

Common Mistakes:

• Confusing URL strings with view names
• Assuming URL ends without trailing slash

4. Identify the error in this urlpatterns list:

from django.urls import path
from . import views

urlpatterns = [
    path('home/', views.home_view),
    path('about/', views.about_view
]

medium

A. Missing closing parenthesis in second path()

B. Using views instead of view functions

C. Incorrect import statement

D. urlpatterns should be a dictionary, not a list

Solution

1. Step 1: Check syntax of each path() call

   The second path('about/', views.about_view is missing a closing parenthesis.

2. Step 2: Verify other parts

   Imports and list structure are correct; views is correctly used to reference functions.

3. Final Answer:

   Missing closing parenthesis in second path() -> Option A

4. Quick Check:

   Every path() needs matching parentheses [OK]

Hint: Count parentheses in each path() call [OK]

Common Mistakes:

• Forgetting closing parenthesis
• Thinking urlpatterns is a dictionary

5. You want to include URL patterns from an app called blog inside your main urlpatterns. Which is the correct way to do this?

hard

A. path('blog/', include('blog.urls'))

B. path('blog/', blog.urls)

C. include('blog.urls')

D. path('blog/', 'blog.urls')

Solution

1. Step 1: Understand how to include app URLs

   Use include() inside path() to add app URL patterns under a prefix.

2. Step 2: Check other options

   include('blog.urls') misses the path() wrapper; path('blog/', blog.urls) misses include(); path('blog/', 'blog.urls') passes a string instead of include().

3. Final Answer:

   path('blog/', include('blog.urls')) -> Option A

4. Quick Check:

   Use include() inside path() for app URLs [OK]

Hint: Use include() inside path() to add app URLs [OK]

Common Mistakes:

• Forgetting to use include()
• Passing string directly without include()
• Not wrapping include() inside path()