The 'decr' function is used in memcached when you need to decrement a numeric value of a specific key. This is commonly used in scenarios like rate limiting, counters, and inventory management where you need to reduce the value by a certain amount.
To perform decrement operations, we will use
pymemcache, which is a comprehensive, fast, pure-Python client library for interacting with memcached.
Firstly, install the pymemcache library if you haven't:
The basic usage of
decr operation is as follows:
In this example, we first set a key 'counter' with a value of 100. Then we decrease it by 10 using the
decr method. Finally, we retrieve the value which should now be 90.
decroperation will return an error.
Q: What happens if the value after decrement becomes negative? A: If a decrement operation would result in a negative number, memcached automatically resets the value to 0.
Q: What happens if I try to decrement a non-existing key? A: If you try to decrement a key that does not exist in memcached, an error will be returned.