Memcached

Memcached was written to reduce the number of database queries, which is built as a general purpose ultrafast memory-based caching service.

(Work in a highly scalable manner, that you can run memcached in a consistent-hashing-based cluster and your cache will be partitioned across as many machines as you like.)

Use memcache in Python

1. Install related packages

pip3 install python-memcached

1. Use memcached in python

import memcache
memc = memcache.Client(['127.0.0.1:11211'])

import sys
import MySQLdb
import memcache
memc = memcache.Client(['127.0.0.1:11211'], debug=1);
try:
    conn = MySQLdb.connect (host = "localhost",
                            user = "sakila",
                            passwd = "password",
                            db = "sakila")
except MySQLdb.Error, e:
     print "Error %d: %s" % (e.args[0], e.args[1])
     sys.exit (1)
popularfilms = memc.get('top5films')
if not popularfilms:
    cursor = conn.cursor()
    cursor.execute('select film_id,title from film order by rental_rate desc limit 5')
    rows = cursor.fetchall()
    memc.set('top5films',rows,60)
    print "Updated memcached with MySQL data"
else:
    print "Loaded data from memcached"
    for row in popularfilms:
        print "%s, %s" % (row[0], row[1])


Python memcache Function    Equivalent Generic Function
get()                           Generic get().
get_multi(keys) 
        Gets multiple values from the supplied array of keys. Returns a hash reference of key/value pairs.
set()                            Generic set().
set_multi(dict [, expiry [, key_prefix]])    
        Sets multiple key/value pairs from the supplied dict.
add()                            Generic add().
replace()                     Generic replace().
prepend(key, value [, expiry])  Prepends the supplied value to the value of the existing key.
append(key, value [, expiry[)      Appends the supplied value to the value of the existing key.
delete()                     Generic delete().
delete_multi(keys [, expiry [, key_prefix]] )    
         Deletes all the keys from the hash matching each string in the array keys.
incr()    Generic incr().
decr()    Generic decr().

[MySQL Memcached](https://dev.mysql.com/doc/mysql-ha-scalability/en/ha-memcached-interfaces-python.html\)