path function for routes in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Django URL pattern matching?

Given the following URL pattern and a request to '/blog/42/', what view will be called and what will be the value of the captured parameter?

Django

from django.urls import path
from . import views

urlpatterns = [
    path('blog/<int:post_id>/', views.post_detail, name='post_detail'),
]

# Assume views.post_detail is defined to accept post_id as argument.

A The view 'post_detail' is called with post_id='blog/42/'

B The view 'post_detail' is called with post_id='42/'

C No view is called because the URL does not match

D The view 'post_detail' is called with post_id=42

💡 Hint

Look at how the path converter works in the URL pattern.

The path function captures the integer part after 'blog/' and passes it as an integer argument named post_id to the view.

📝 Syntax

intermediate

Which option correctly defines a path with a string parameter named 'username'?

Select the correct Django path function usage to capture a string parameter 'username' from the URL '/user//'

A path('user/<str:username>/', views.profile, name='profile')

B path('user/<username>/', views.profile, name='profile')

C path('user/<int:username>/', views.profile, name='profile')

D path('user/<slug:username>/', views.profile, name='profile')

💡 Hint

Remember the syntax for path converters in Django's path function.

The correct syntax to capture a string parameter is . Omitting the converter defaults to str but is not recommended. Using int or slug changes the expected format.

🔧 Debug

advanced

Why does this URL pattern cause a runtime error?

Examine the following urlpatterns list and identify why it causes an error when Django starts.

Django

from django.urls import path

urlpatterns = [
    path('article/<int:id>/', views.article_detail),
    path('article/<int:id>/', views.article_edit),
]

A Missing 'name' argument in path causes runtime error.

B The views module is not imported, causing NameError.

C Duplicate URL patterns with the same path cause ambiguity and Django raises an error.

D The variable name 'id' is reserved and causes error.

💡 Hint

Check if all referenced modules are imported.

The code references 'views.article_detail' and 'views.article_edit' without importing the 'views' module, causing a NameError when Django loads the URL configuration.

❓ state_output

advanced

What is the value of 'kwargs' passed to the view for this path?

Given the URL pattern and a request to '/shop/electronics/123/', what is the kwargs dictionary passed to the view?

Django

path('shop/<slug:category>/<int:item_id>/', views.item_detail, name='item_detail')

A {'category': 'electronics', 'item_id': 123}

B {'category': 'electronics/123', 'item_id': None}

C {'category': 'shop', 'item_id': 'electronics'}

D {} (empty dictionary)

💡 Hint

Look at how multiple path converters capture parts of the URL.

The slug converter captures 'electronics' as category and int converter captures 123 as item_id.

🧠 Conceptual

expert

Which option best explains the difference between path() and re_path() in Django routing?

Choose the most accurate explanation about the difference between path() and re_path() functions in Django URL configuration.

A path() automatically escapes special characters; re_path() does not.

B path() supports only static URLs; re_path() supports dynamic URLs with parameters.

C path() uses simpler, readable converters for common patterns; re_path() uses full regular expressions for complex matching.

D path() is deprecated and replaced by re_path() in modern Django versions.

💡 Hint

Think about the syntax and flexibility differences between path and re_path.

path() provides easy-to-read converters like , , while re_path() allows full regex for advanced patterns.

Practice

1. What is the main purpose of the path function in Django?

easy

A. To run background tasks

B. To connect a URL pattern to a view function or class

C. To style HTML pages

D. To create a database model

Solution

1. Step 1: Understand the role of URL routing

   Django uses URL routing to decide which code runs when a user visits a URL.

2. Step 2: Identify what path does

   The path function links a URL pattern to a view function or class that handles the request.

3. Final Answer:

   To connect a URL pattern to a view function or class -> Option B

4. Quick Check:

   URL routing = connect URL to view [OK]

Hint: Remember: path links URLs to code that runs [OK]

Common Mistakes:

• Confusing path with database models
• Thinking path styles HTML
• Assuming path runs background tasks

2. Which of the following is the correct syntax to define a route using path in Django?

easy

A. path('home/', views.home_view, name='home')

B. path = 'home/' views.home_view

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

D. path('home', views.home_view, 'home')

Solution

1. Step 1: Recall the path function signature

   The path function takes at least two arguments: the URL pattern string and the view function. Optionally, a name argument can be added.

2. Step 2: Check each option's syntax

   path('home/' views.home_view') misses comma between arguments, invalid syntax. path = 'home/' views.home_view is invalid syntax. path('home/', views.home_view, name='home') correctly uses path('home/', views.home_view, name='home'). path('home', views.home_view, 'home') has incorrect argument order and missing keyword.

3. Final Answer:

   path('home/', views.home_view, name='home') -> Option A

4. Quick Check:

   Correct syntax includes URL, view, and optional name [OK]

Hint: Use path('url/', view, name='route_name') format [OK]

Common Mistakes:

• Omitting commas between arguments
• Missing quotes around URL string
• Passing name without keyword

3. Given the following URL pattern:

path('article//', views.article_detail, name='article_detail')

What URL will match this pattern?

medium

A. /article/42/

B. /article/abc/

C. /article/42

D. /article//

Solution

1. Step 1: Understand the dynamic part in the URL pattern

   The pattern uses <int:id> which means it expects an integer value in that part of the URL.

2. Step 2: Match each option to the pattern

   /article/42/ has an integer 42 and ends with a slash, matching the pattern exactly. /article/abc/ has letters 'abc' which is not an integer. /article/42 misses the trailing slash. /article// has no value where integer is expected.

3. Final Answer:

   /article/42/ -> Option A

4. Quick Check:

   Integer in URL with trailing slash matches [OK]

Hint: Dynamic parts need correct type and trailing slash [OK]

Common Mistakes:

• Ignoring trailing slash
• Using wrong data type in URL
• Leaving dynamic part empty

4. Identify the error in this Django URL pattern:

path('profile/<username>/', views.profile_view, name='profile')

medium

A. Missing comma between arguments

B. Incorrect view function name

C. Missing type converter for <username>

D. URL pattern should not have dynamic parts

Solution

1. Step 1: Check the dynamic part syntax

   Django requires a type converter like str or int inside angle brackets for dynamic parts, e.g., <str:username>.

2. Step 2: Analyze the given pattern

   The pattern uses <username> without a type converter, which is invalid syntax.

3. Final Answer:

   Missing type converter for <username> -> Option C

4. Quick Check:

   Dynamic parts need type like str or int [OK]

Hint: Always add type before variable in < > [OK]

Common Mistakes:

• Leaving out type converter in dynamic URL parts
• Forgetting commas between arguments
• Assuming any string works as dynamic part

5. You want to create a route that matches URLs like /blog/2024/06/ where the year and month are dynamic integers. Which of the following path definitions is correct?

hard

A. path('blog/<year>/<month>/', views.blog_archive, name='blog_archive')

B. path('blog///', views.blog_archive, name='blog_archive')

C. path('blog//<month>/', views.blog_archive, name='blog_archive')

D. path('blog///', views.blog_archive, name='blog_archive')

Solution

1. Step 1: Understand the correct syntax for dynamic URL parts

   The correct format is <type:variable>, for example <int:year>.

2. Step 2: Evaluate each option

   path('blog///', views.blog_archive, name='blog_archive') uses correct syntax for both year and month as integers. path('blog///', views.blog_archive, name='blog_archive') reverses type and variable order, which is invalid. path('blog//<month>/', views.blog_archive, name='blog_archive') misses type for month. path('blog/<year>/<month>/', views.blog_archive, name='blog_archive') misses types for both year and month.

3. Final Answer:

   path('blog/<int:year>/<int:month>/', views.blog_archive, name='blog_archive') -> Option D

4. Quick Check:

   Use <int:var> for integer dynamic parts [OK]

Hint: Use for integer parts in URL [OK]

Common Mistakes:

• Swapping type and variable order
• Omitting type converters
• Using unknown types