XREVRANGE
is a Redis operation that allows you to retrieve items from a stream in reverse order, starting at the latest item. In Python, this operation can be particularly useful when you need to fetch the most recent entries from a stream, for instance, in applications such as event sourcing, message queuing, or logging.
Here's an example of how to use XREVRANGE
with redis-py, a Python interface to Redis:
import redis r = redis.Redis() # Add some data to 'mystream' for i in range(10): r.xadd('mystream', {'field': 'value' + str(i)}) # Fetch the last 5 items from 'mystream' items = r.xrevrange('mystream', count=5) print(items)
This code first adds some test data into the stream named 'mystream'. Then, it uses xrevrange
to fetch the latest 5 items from 'mystream'. The output will be the five most recent entries in reverse order.
When using XREVRANGE
:
count
.A common mistake is not understanding the order of returned items. The XREVRANGE
command returns items in reverse order, so the most recently added entry comes first.
Q: Can I use XREVRANGE to fetch items from multiple streams?
A: No, XREVRANGE
only works with a single stream. If you need to fetch data from multiple streams, you will have to execute the command for each stream separately.
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement.