urlpatterns list structure in Django - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the urlpatterns list in Django?

The urlpatterns list tells Django which URLs to listen for and which views to run when those URLs are requested.

beginner

How do you add a new URL pattern to the urlpatterns list?

You add a new URL pattern by appending a path() or re_path() function call with the URL pattern string and the view function or class.

beginner

What does the path() function inside urlpatterns do?

The path() function defines a URL pattern and connects it to a view that handles requests to that URL.

intermediate

Why is the order of patterns in urlpatterns important?

Django checks URL patterns in order. The first pattern that matches the requested URL is used, so order affects which view runs.

beginner

What type of object is urlpatterns in Django?

urlpatterns is a Python list containing URL pattern objects created by path(), re_path(), or include().

What does the urlpatterns list contain?

A URL patterns linked to views

B Database models

C HTML templates

D Static files

The urlpatterns list contains URL patterns that connect URLs to views.

Which function is commonly used to define a URL pattern in urlpatterns?

A render()

B path()

C include()

D filter()

path() is used to define URL patterns in Django.

What happens if two URL patterns in urlpatterns match the same URL?

A The first matching pattern is used

B Both views run

C An error is raised

D The last matching pattern is used

Django uses the first URL pattern that matches the requested URL.

What type of data structure is urlpatterns?

A Set

B Dictionary

C List

D Tuple

urlpatterns is a Python list.

Which of these is NOT a valid element inside urlpatterns?

A path()

B re_path()

C include()

D random strings

Only URL pattern functions like path(), re_path(), or include() should be inside urlpatterns, not random strings.

Explain how the urlpatterns list works in Django and why its order matters.

Think about how Django decides which view to run when a URL is requested.

Describe how to add a new URL route to a Django project using urlpatterns.

Focus on the syntax and components needed for a new route.

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()