Troubleshooting Wrong Type Error in Python Redis GET (Detailed Guide w/ Code Examples)
Use Case(s)
Encountering a WRONGTYPE error while using Python Redis GET typically happens when trying to perform an operation that is incompatible with the data type of the stored value. This issue often occurs when using data structures like lists, sets, or hashes.
Code Examples
Let's look at two examples where we try to fetch a list and a set as if they were strings - this will throw WRONGTYPE errors.
Example 1 - Fetching a List
import redis r = redis.Redis() r.rpush('mylist', 'item') # Add item into a list print(r.get('mylist')) # Attempt to get the list as a string
This code raises a redis.exceptions.ResponseError: WRONGTYPE Operation against a key holding the wrong kind of value
because we're trying to get a list as if it was a string.
Example 2 - Fetching a Set
import redis r = redis.Redis() r.sadd('myset', 'item') # Add item into a set print(r.get('myset')) # Attempt to get the set as a string
This code also raises a WRONGTYPE error for similar reasons.
Best Practices
Ensure you're using the correct commands associated with the particular data type of the stored value. For example, use LRANGE
to retrieve lists, SMEMBERS
for sets, and so on.
Common Mistakes
A common mistake leading to the WRONGTYPE error is not understanding the types of data structures in Redis and their associated commands. Python's redis
module adheres closely to the command structure of Redis itself, so knowledge of Redis data types is crucial.
FAQs
Q: How do I know which type of value a key holds?
A: You can use the TYPE
command. If you're unsure what type of data a key holds, you can run r.type('mykey')
, which will return the type of the key.
Was this content helpful?
Similar Code Examples
- Getting All Keys Matching a Pattern in Redis using Python
- Getting the Length of a Redis List in Python
- Getting Server Info from Redis in Python
- Getting Number of Connections in Redis Using Python
- Getting Current Redis Version in Python
- Getting Memory Stats in Redis using Python
- Redis Get All Databases in Python
- Redis Get All Keys and Values in Python
- Retrieving a Key by Value in Redis Using Python
- Python Redis: Get Config Settings
- Getting All Hash Keys Using Redis in Python
- Get Total Commands Processed in Redis Using Python
Switch & save up to 80%
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement. Instantly experience up to a 25X boost in performance and 80% reduction in cost