Throttling for rate limiting in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the throttle class for rate limiting in Django REST Framework.

Django

from rest_framework.throttling import [1]

Drag options to blanks, or click blank then click option'

AUserRateThrottle

BAPIView

CIsAuthenticated

DSessionAuthentication

Attempts:

3 left

💡 Hint

Common Mistakes

Importing authentication or permission classes instead of throttle classes.

Using classes unrelated to rate limiting.

The UserRateThrottle class is used to apply rate limiting per user in Django REST Framework.

2fill in blank

medium

Complete the code to set the throttle classes in a Django REST Framework view.

Django

class MyView(APIView):
    throttle_classes = [[1]]

Drag options to blanks, or click blank then click option'

ASessionAuthentication

BAllowAny

CIsAuthenticated

DUserRateThrottle

Attempts:

3 left

💡 Hint

Common Mistakes

Using permission classes instead of throttle classes.

Forgetting to put the class inside a list.

The throttle_classes attribute expects throttle classes like UserRateThrottle to limit request rates.

3fill in blank

hard

Fix the error in the throttle rate setting in Django REST Framework settings.

Django

"DEFAULT_THROTTLE_RATES": {
    "user": "[1]"
}

Drag options to blanks, or click blank then click option'

A1000/hour

B1000 per hour

C100/hour

D1000/hourly

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect time units like 'hourly'.

Adding extra words like 'per'.

The throttle rate must be a string with a number and a time unit separated by a slash, like '100/hour'.

4fill in blank

hard

Fill both blanks to create a custom throttle class that limits requests to 10 per minute.

Django

from rest_framework.throttling import [1]

class CustomThrottle([2]):
    rate = '10/minute'

Drag options to blanks, or click blank then click option'

AUserRateThrottle

BBaseThrottle

CSimpleRateThrottle

DAnonRateThrottle

Attempts:

3 left

💡 Hint

Common Mistakes

Inheriting from the wrong base class.

Importing a class but not using it correctly.

Custom throttles usually inherit from SimpleRateThrottle to define a custom rate. The import should be SimpleRateThrottle since the class inherits from it.

5fill in blank

hard

Fill all three blanks to apply throttling globally in Django REST Framework settings.

Django

REST_FRAMEWORK = {
    'DEFAULT_THROTTLE_CLASSES': [
        '[1]',
    ],
    'DEFAULT_THROTTLE_RATES': {
        '[2]': '[3]'
    }
}

Drag options to blanks, or click blank then click option'

Arest_framework.throttling.UserRateThrottle

Buser

C1000/day

Drest_framework.permissions.IsAuthenticated

Attempts:

3 left

💡 Hint

Common Mistakes

Using permission classes instead of throttle classes in settings.

Mismatching throttle rate keys and classes.

To enable throttling globally, set DEFAULT_THROTTLE_CLASSES to the full path of the throttle class, and define DEFAULT_THROTTLE_RATES with the key matching the throttle scope and the rate string.

Practice

1. What is the main purpose of throttling in Django REST Framework?

easy

A. To cache API responses for faster access

B. To limit the number of requests a user can make in a given time period

C. To authenticate users before accessing the API

D. To speed up the response time of the server

Solution

1. Step 1: Understand throttling concept

   Throttling is designed to control how many requests a user can send to the server in a set time.

2. Step 2: Identify purpose in Django REST Framework

   It prevents abuse by limiting request rates, not speeding responses or authentication.

3. Final Answer:

   To limit the number of requests a user can make in a given time period -> Option B

4. Quick Check:

   Throttling = request limit [OK]

Hint: Throttling controls request counts per time [OK]

Common Mistakes:

• Confusing throttling with authentication
• Thinking throttling speeds up responses
• Mixing throttling with caching

2. Which of the following is the correct way to set a throttle rate of 10 requests per minute in a custom throttle class?

easy

A. rate = '10/minute'

B. rate = '10/second'

C. rate = 'minute/10'

D. rate = '10 requests per minute'

Solution

1. Step 1: Recall throttle rate format

   The rate must be a string with number and time unit separated by a slash, e.g., '10/minute'.

2. Step 2: Match correct syntax

   Only '10/minute' matches the required format; others are invalid or incorrect syntax.

3. Final Answer:

   rate = '10/minute' -> Option A

4. Quick Check:

   Throttle rate format = 'number/time' [OK]

Hint: Throttle rate uses 'number/time' string format [OK]

Common Mistakes:

• Using spaces or words instead of slash format
• Swapping number and time units
• Using unsupported time units

3. Given this view with throttling applied:

from rest_framework.throttling import UserRateThrottle

class MyThrottle(UserRateThrottle):
    rate = '3/minute'

class MyView(APIView):
    throttle_classes = [MyThrottle]

    def get(self, request):
        return Response({'message': 'Hello'})

What happens if a user makes 4 GET requests within one minute?

medium

A. The 4th request is delayed but eventually succeeds

B. All 4 requests succeed with status 200

C. The 4th request is blocked with a 429 Too Many Requests error

D. The server crashes due to too many requests

Solution

1. Step 1: Understand throttle rate and behavior

   The throttle allows 3 requests per minute per user; the 4th exceeds the limit.

2. Step 2: Identify response to exceeding limit

   When limit is exceeded, Django REST Framework returns HTTP 429 error blocking the request.

3. Final Answer:

   The 4th request is blocked with a 429 Too Many Requests error -> Option C

4. Quick Check:

   Requests > rate limit = 429 error [OK]

Hint: Requests over limit get 429 error [OK]

Common Mistakes:

• Assuming all requests succeed
• Thinking requests get delayed instead of blocked
• Believing server crashes on too many requests

4. Identify the error in this custom throttle class:

from rest_framework.throttling import SimpleRateThrottle

class CustomThrottle(SimpleRateThrottle):
    scope = 'custom'

    def get_cache_key(self, request, view):
        return request.user.id

# settings.py
REST_FRAMEWORK = {
    'DEFAULT_THROTTLE_RATES': {
        'custom': '5/minute'
    }
}

medium

A. get_cache_key should return a string, but returns an integer

B. scope should be set to 'rate' instead of 'custom'

C. DEFAULT_THROTTLE_RATES key 'custom' is missing a time unit

D. CustomThrottle must inherit from UserRateThrottle, not SimpleRateThrottle

Solution

1. Step 1: Check get_cache_key return type

   The method returns request.user.id, which is an integer, but cache keys must be strings.

2. Step 2: Validate other parts

   Scope 'custom' matches the throttle rate key, and inheritance from SimpleRateThrottle is valid.

3. Final Answer:

   get_cache_key should return a string, but returns an integer -> Option A

4. Quick Check:

   Cache key must be string [OK]

Hint: Cache keys must be strings, not integers [OK]

Common Mistakes:

• Returning non-string cache keys
• Misnaming throttle scope
• Confusing throttle class inheritance

5. You want to apply different throttle rates for authenticated and anonymous users in Django REST Framework. Which approach correctly implements this?

hard

A. Set a single throttle class with rate '10/minute' and check user status inside get_cache_key

B. Use middleware to block anonymous users after 5 requests per minute instead of throttling classes

C. Apply throttling only to authenticated users by setting throttle_classes conditionally in the view

D. Use two throttle classes: one with 'user' scope for authenticated, one with 'anon' scope for anonymous, and add both to the view's throttle_classes

Solution

1. Step 1: Understand throttling for different user types

   Django REST Framework supports multiple throttle classes to handle different user types separately.

2. Step 2: Apply correct method

   Using two throttle classes with 'user' and 'anon' scopes and adding both to throttle_classes is the standard way.

3. Final Answer:

   Use two throttle classes: one with 'user' scope for authenticated, one with 'anon' scope for anonymous, and add both to the view's throttle_classes -> Option D

4. Quick Check:

   Multiple throttle classes handle user types separately [OK]

Hint: Use separate throttle classes for user and anon [OK]

Common Mistakes:

• Trying to handle both user types in one throttle class
• Using middleware instead of throttle classes
• Conditionally setting throttle_classes in the view