Identify the error in this Flask Redis subscription code: ```python pubsub = redis_client.pubsub() pubsub.subscribe('channel1') message = pubsub.get_message() print(message['data']) ``` If no message was published yet, what happens?

medium📝 Debug Q6 of 15

Flask - Background Tasks

ATypeError because message is None and cannot be subscripted

BNo error, prints 1

CKeyError because 'data' key is missing

DAttributeError because get_message is not a method

Step-by-Step Solution

Solution:

Step 1: Understand pubsub.get_message after subscribe
The first call to get_message() returns the subscription confirmation {'type': 'subscribe', 'channel': b'channel1', 'data': 1}.
Step 2: Analyze print statement
message['data'] is 1 (integer), so it prints 1 with no error.
Final Answer:
No error, prints 1 -> Option B
Quick Check:
Subscription confirmation has 'data': 1 [OK]

Quick Trick: First get_message after subscribe returns confirmation with data=1 [OK]

Common Mistakes:

MISTAKES

Forgetting subscription confirmation message
Assuming get_message returns None immediately
Expecting KeyError instead of no error

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Identify the error in this Flask Redis subscription code: ```python pubsub = redis_client.pubsub() pubsub.subscribe('channel1') message = pubsub.get_message() print(message['data']) ``` If no message was published yet, what happens?

Step 1: Understand pubsub.get_message after subscribe

Step 2: Analyze print statement

Final Answer:

Quick Check:

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