[Solved] Consider this simplified server logic for handling POST requests with idempotency keys: stored_keys = {} def handle_request(idempotency_key, data): if idempotency_key in stored_keys:... | Rest API

Rest API - Advanced Patterns

Consider this simplified server logic for handling POST requests with idempotency keys:

stored_keys = {}

def handle_request(idempotency_key, data):
    if idempotency_key in stored_keys:
        return stored_keys[idempotency_key]
    response = process_data(data)
    stored_keys[idempotency_key] = response
    return response

# Client sends:
print(handle_request('abc123', 'order1'))
print(handle_request('abc123', 'order1'))
print(handle_request('xyz789', 'order2'))

What will be the output?

ANone, None, None

Bprocess_data output for order1, None, process_data output for order2

Cprocess_data output for order1, process_data output for order2, process_data output for order2

Dprocess_data output for order1, process_data output for order1, process_data output for order2

Step-by-Step Solution

Solution:

Step 1: Analyze first call with key 'abc123'
Key not in stored_keys, so process_data('order1') runs, result saved and returned.
Step 2: Analyze second call with same key 'abc123'
Key found, stored response returned without reprocessing.
Step 3: Analyze third call with new key 'xyz789'
Key not found, process_data('order2') runs, result saved and returned.
Final Answer:
process_data output for order1, process_data output for order1, process_data output for order2 -> Option D
Quick Check:
Repeated key returns cached response [OK]

Quick Trick: Repeated keys return cached response, new keys process data [OK]

Common Mistakes:

MISTAKES

Assuming second call reprocesses data
Confusing keys and responses
Thinking None is returned on repeats

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Consider this simplified server logic for handling POST requests with idempotency keys:

Step 1: Analyze first call with key 'abc123'

Step 2: Analyze second call with same key 'abc123'

Step 3: Analyze third call with new key 'xyz789'

Final Answer:

Quick Check:

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