Backends

class redisdb.backends.RedisRing(location, params)

RedisRing backend which writes only to one Redis server based on key.

RedisRing is only a proxy to underlying ConstRedis objects, which represents each Redis instance. It has the same methods set as ConstRedis. Individual nodes can be accessed through nodes attribute.

RedisRing is better suited for using Redis as memcached replacement. With one server failure data kept on that server have to be recreated.

class redisdb.backends.RedisCopy(location, params)

Redis backend which writes to all Redis servers.

RedisCopy is only a proxy to underlying ConstRedis objects, which represents each Redis instance. It has the same methods set as ConstRedis. Individual nodes can be accessed through nodes attribute.

Fetching is done only from one server based on key just like in RedisRing. RedisCopy can be seen like master/master configuration where synchronization isn’t done by Redis itself but by clients. It’s well suited for storing data that should be available even if one server goes down.

class redisdb.backends.ConstRedis(*args, **kwargs)

Redis client that adds consistent hashing to StrictRedis.

append(key, value)

Appends the string value to the value at key. If key doesn’t already exist, create it with a value of value. Returns the new length of the value at key.

bgrewriteaof()

Tell the Redis server to rewrite the AOF file from data in memory.

bgsave()

Tell the Redis server to save its data to disk. Unlike save(), this method is asynchronous and returns immediately.

bitcount(key, start=None, end=None)

Returns the count of set bits in the value of key. Optional start and end paramaters indicate which bytes to consider

bitop(operation, dest, *keys)

Perform a bitwise operation using operation between keys and store the result in dest.

bitpos(key, bit, start=None, end=None)

Return the position of the first bit set to 1 or 0 in a string. start and end difines search range. The range is interpreted as a range of bytes and not a range of bits, so start=0 and end=2 means to look at the first three bytes.

blpop(keys, timeout=0)

LPOP a value off of the first non-empty list named in the keys list.

If none of the lists in keys has a value to LPOP, then block for timeout seconds, or until a value gets pushed on to one of the lists.

If timeout is 0, then block indefinitely.

brpop(keys, timeout=0)

RPOP a value off of the first non-empty list named in the keys list.

If none of the lists in keys has a value to LPOP, then block for timeout seconds, or until a value gets pushed on to one of the lists.

If timeout is 0, then block indefinitely.

brpoplpush(src, dst, timeout=0)

Pop a value off the tail of src, push it on the head of dst and then return it.

This command blocks until a value is in src or until timeout seconds elapse, whichever is first. A timeout value of 0 blocks forever.

client_getname()

Returns the current connection name

client_kill(address)

Disconnects the client at address (ip:port)

client_list()

Returns a list of currently connected clients

client_setname(name)

Sets the current connection name

config_get(pattern='*')

Return a dictionary of configuration based on the pattern

config_resetstat()

Reset runtime statistics

config_rewrite()

Rewrite config file with the minimal change to reflect running config

config_set(name, value)

Set config item name with value

dbsize()

Returns the number of keys in the current database

debug_object(key)

Returns version specific meta information about a given key

decr(name, amount=1)

Decrements the value of key by amount. If no key exists, the value will be initialized as 0 - amount

delete(*names)

Delete one or more keys specified by names

dump(name)

Return a serialized version of the value stored at the specified key. If key does not exist a nil bulk reply is returned.

echo(value)

Echo the string back from the server

eval(script, numkeys, *keys_and_args)

Execute the Lua script, specifying the numkeys the script will touch and the key names and argument values in keys_and_args. Returns the result of the script.

In practice, use the object returned by register_script. This function exists purely for Redis API completion.

evalsha(sha, numkeys, *keys_and_args)

Use the sha to execute a Lua script already registered via EVAL or SCRIPT LOAD. Specify the numkeys the script will touch and the key names and argument values in keys_and_args. Returns the result of the script.

In practice, use the object returned by register_script. This function exists purely for Redis API completion.

execute_command(*args, **options)

Execute a command and return a parsed response

exists(name)

Returns a boolean indicating whether key name exists

expire(name, time)

Set an expire flag on key name for time seconds. time can be represented by an integer or a Python timedelta object.

expireat(name, when)

Set an expire flag on key name. when can be represented as an integer indicating unix time or a Python datetime object.

flushall()

Delete all keys in all databases on the current host

flushdb()

Delete all keys in the current database

from_url(url, db=None, **kwargs)

Return a Redis client object configured from the given URL.

For example:

redis://[:password]@localhost:6379/0
unix://[:password]@/path/to/socket.sock?db=0

There are several ways to specify a database number. The parse function will return the first specified option:

1. A db querystring option, e.g. redis://localhost?db=0
2. If using the redis:// scheme, the path argument of the url, e.g. redis://localhost/0
3. The db argument to this function.

If none of these options are specified, db=0 is used.

Any additional querystring arguments and keyword arguments will be passed along to the ConnectionPool class’s initializer. In the case of conflicting arguments, querystring arguments always win.

get(name)

Return the value at key name, or None if the key doesn’t exist

getbit(name, offset)

Returns a boolean indicating the value of offset in name

getrange(key, start, end)

Returns the substring of the string value stored at key, determined by the offsets start and end (both are inclusive)

getset(name, value)

Sets the value at key name to value and returns the old value at key name atomically.

hdel(name, *keys)

Delete keys from hash name

hexists(name, key)

Returns a boolean indicating if key exists within hash name

hget(name, key)

Return the value of key within the hash name

hgetall(name)

Return a Python dict of the hash’s name/value pairs

hincrby(name, key, amount=1)

Increment the value of key in hash name by amount

hincrbyfloat(name, key, amount=1.0)

Increment the value of key in hash name by floating amount

hkeys(name)

Return the list of keys within hash name

hlen(name)

Return the number of elements in hash name

hmget(name, keys, *args)

Returns a list of values ordered identically to keys

hmset(name, mapping)

Set key to value within hash name for each corresponding key and value from the mapping dict.

hscan(name, cursor=0, match=None, count=None)

Incrementally return key/value slices in a hash. Also return a cursor indicating the scan position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

hscan_iter(name, match=None, count=None)

Make an iterator using the HSCAN command so that the client doesn’t need to remember the cursor position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

hset(name, key, value)

Set key to value within hash name Returns 1 if HSET created a new field, otherwise 0

hsetnx(name, key, value)

Set key to value within hash name if key does not exist. Returns 1 if HSETNX created a field, otherwise 0.

hvals(name)

Return the list of values within hash name

incr(name, amount=1)

Increments the value of key by amount. If no key exists, the value will be initialized as amount

incrby(name, amount=1)

Increments the value of key by amount. If no key exists, the value will be initialized as amount

incrbyfloat(name, amount=1.0)

Increments the value at key name by floating amount. If no key exists, the value will be initialized as amount

info(section=None)

Returns a dictionary containing information about the Redis server

The section option can be used to select a specific section of information

The section option is not supported by older versions of Redis Server, and will generate ResponseError

keys(pattern='*')

Returns a list of keys matching pattern

lastsave()

Return a Python datetime object representing the last time the Redis database was saved to disk

lindex(name, index)

Return the item from list name at position index

Negative indexes are supported and will return an item at the end of the list

linsert(name, where, refvalue, value)

Insert value in list name either immediately before or after [where] refvalue

Returns the new length of the list on success or -1 if refvalue is not in the list.

llen(name)

Return the length of the list name

lock(name, timeout=None, sleep=0.1, blocking_timeout=None, lock_class=None, thread_local=True)

Return a new Lock object using key name that mimics the behavior of threading.Lock.

If specified, timeout indicates a maximum life for the lock. By default, it will remain locked until release() is called.

sleep indicates the amount of time to sleep per loop iteration when the lock is in blocking mode and another client is currently holding the lock.

blocking_timeout indicates the maximum amount of time in seconds to spend trying to acquire the lock. A value of None indicates continue trying forever. blocking_timeout can be specified as a float or integer, both representing the number of seconds to wait.

lock_class forces the specified lock implementation.

thread_local indicates whether the lock token is placed in thread-local storage. By default, the token is placed in thread local storage so that a thread only sees its token, not a token set by another thread. Consider the following timeline:

time: 0, thread-1 acquires my-lock, with a timeout of 5 seconds.

thread-1 sets the token to “abc”

time: 1, thread-2 blocks trying to acquire my-lock using the

Lock instance.

time: 5, thread-1 has not yet completed. redis expires the lock

key.

time: 5, thread-2 acquired my-lock now that it’s available.

thread-2 sets the token to “xyz”

time: 6, thread-1 finishes its work and calls release(). if the

token is not stored in thread local storage, then thread-1 would see the token value as “xyz” and would be able to successfully release the thread-2’s lock.

In some use cases it’s necessary to disable thread local storage. For example, if you have code where one thread acquires a lock and passes that lock instance to a worker thread to release later. If thread local storage isn’t disabled in this case, the worker thread won’t see the token set by the thread that acquired the lock. Our assumption is that these cases aren’t common and as such default to using thread local storage.

lpop(name)

Remove and return the first item of the list name

lpush(name, *values)

Push values onto the head of the list name

lpushx(name, value)

Push value onto the head of the list name if name exists

lrange(name, start, end)

Return a slice of the list name between position start and end

start and end can be negative numbers just like Python slicing notation

lrem(name, count, value)

Remove the first count occurrences of elements equal to value from the list stored at name.

The count argument influences the operation in the following ways:

count > 0: Remove elements equal to value moving from head to tail. count < 0: Remove elements equal to value moving from tail to head. count = 0: Remove all elements equal to value.

lset(name, index, value)

Set position of list name to value

ltrim(name, start, end)

Trim the list name, removing all values not within the slice between start and end

start and end can be negative numbers just like Python slicing notation

mget(keys, *args)

Returns a list of values ordered identically to keys

move(name, db)

Moves the key name to a different Redis database db

mset(*args, **kwargs)

Sets key/values based on a mapping. Mapping can be supplied as a single dictionary argument or as kwargs.

msetnx(*args, **kwargs)

Sets key/values based on a mapping if none of the keys are already set. Mapping can be supplied as a single dictionary argument or as kwargs. Returns a boolean indicating if the operation was successful.

object(infotype, key)

Return the encoding, idletime, or refcount about the key

parse_response(connection, command_name, **options)

Parses a response from the Redis server

persist(name)

Removes an expiration on name

pexpire(name, time)

Set an expire flag on key name for time milliseconds. time can be represented by an integer or a Python timedelta object.

pexpireat(name, when)

Set an expire flag on key name. when can be represented as an integer representing unix time in milliseconds (unix time * 1000) or a Python datetime object.

pfadd(name, *values)

Adds the specified elements to the specified HyperLogLog.

pfcount(name)

Return the approximated cardinality of the set observed by the HyperLogLog at key.

pfmerge(dest, *sources)

Merge N different HyperLogLogs into a single one.

ping()

Ping the Redis server

pipeline(transaction=True, shard_hint=None)

Return a new pipeline object that can queue multiple commands for later execution. transaction indicates whether all commands should be executed atomically. Apart from making a group of operations atomic, pipelines are useful for reducing the back-and-forth overhead between the client and server.

psetex(name, time_ms, value)

Set the value of key name to value that expires in time_ms milliseconds. time_ms can be represented by an integer or a Python timedelta object

pttl(name)

Returns the number of milliseconds until the key name will expire

publish(channel, message)

Publish message on channel. Returns the number of subscribers the message was delivered to.

pubsub(**kwargs)

Return a Publish/Subscribe object. With this object, you can subscribe to channels and listen for messages that get published to them.

randomkey()

Returns the name of a random key

register_script(script)

Register a Lua script specifying the keys it will touch. Returns a Script object that is callable and hides the complexity of deal with scripts, keys, and shas. This is the preferred way to work with Lua scripts.

rename(src, dst)

Rename key src to dst

renamenx(src, dst)

Rename key src to dst if dst doesn’t already exist

restore(name, ttl, value)

Create a key using the provided serialized value, previously obtained using DUMP.

rpop(name)

Remove and return the last item of the list name

rpoplpush(src, dst)

RPOP a value off of the src list and atomically LPUSH it on to the dst list. Returns the value.

rpush(name, *values)

Push values onto the tail of the list name

rpushx(name, value)

Push value onto the tail of the list name if name exists

sadd(name, *values)

Add value(s) to set name

save()

Tell the Redis server to save its data to disk, blocking until the save is complete

scan(cursor=0, match=None, count=None)

Incrementally return lists of key names. Also return a cursor indicating the scan position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

scan_iter(match=None, count=None)

Make an iterator using the SCAN command so that the client doesn’t need to remember the cursor position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

scard(name)

Return the number of elements in set name

script_exists(*args)

Check if a script exists in the script cache by specifying the SHAs of each script as args. Returns a list of boolean values indicating if if each already script exists in the cache.

script_flush()

Flush all scripts from the script cache

script_kill()

Kill the currently executing Lua script

script_load(script)

Load a Lua script into the script cache. Returns the SHA.

sdiff(keys, *args)

Return the difference of sets specified by keys

sdiffstore(dest, keys, *args)

Store the difference of sets specified by keys into a new set named dest. Returns the number of keys in the new set.

sentinel(*args)

Redis Sentinel’s SENTINEL command.

sentinel_get_master_addr_by_name(service_name)

Returns a (host, port) pair for the given service_name

sentinel_master(service_name)

Returns a dictionary containing the specified masters state.

sentinel_masters()

Returns a list of dictionaries containing each master’s state.

sentinel_monitor(name, ip, port, quorum)

Add a new master to Sentinel to be monitored

sentinel_remove(name)

Remove a master from Sentinel’s monitoring

sentinel_sentinels(service_name)

Returns a list of sentinels for service_name

sentinel_set(name, option, value)

Set Sentinel monitoring parameters for a given master

sentinel_slaves(service_name)

Returns a list of slaves for service_name

set(name, value, ex=None, px=None, nx=False, xx=False)

Set the value at key name to value

ex sets an expire flag on key name for ex seconds.

px sets an expire flag on key name for px milliseconds.

nx if set to True, set the value at key name to value if it

does not already exist.

xx if set to True, set the value at key name to value if it

already exists.

set_response_callback(command, callback)

Set a custom Response Callback

setbit(name, offset, value)

Flag the offset in name as value. Returns a boolean indicating the previous value of offset.

setex(name, time, value)

Set the value of key name to value that expires in time seconds. time can be represented by an integer or a Python timedelta object.

setnx(name, value)

Set the value of key name to value if key doesn’t exist

setrange(name, offset, value)

Overwrite bytes in the value of name starting at offset with value. If offset plus the length of value exceeds the length of the original value, the new value will be larger than before. If offset exceeds the length of the original value, null bytes will be used to pad between the end of the previous value and the start of what’s being injected.

Returns the length of the new string.

shutdown()

Shutdown the server

sinter(keys, *args)

Return the intersection of sets specified by keys

sinterstore(dest, keys, *args)

Store the intersection of sets specified by keys into a new set named dest. Returns the number of keys in the new set.

sismember(name, value)

Return a boolean indicating if value is a member of set name

slaveof(host=None, port=None)

Set the server to be a replicated slave of the instance identified by the host and port. If called without arguments, the instance is promoted to a master instead.

slowlog_get(num=None)

Get the entries from the slowlog. If num is specified, get the most recent num items.

slowlog_len()

Get the number of items in the slowlog

slowlog_reset()

Remove all items in the slowlog

smembers(name)

Return all members of the set name

smove(src, dst, value)

Move value from set src to set dst atomically

sort(name, start=None, num=None, by=None, get=None, desc=False, alpha=False, store=None, groups=False)

Sort and return the list, set or sorted set at name.

start and num allow for paging through the sorted data

by allows using an external key to weight and sort the items.

Use an “*” to indicate where in the key the item value is located

get allows for returning items from external keys rather than the

sorted data itself. Use an “*” to indicate where int he key the item value is located

desc allows for reversing the sort

alpha allows for sorting lexicographically rather than numerically

store allows for storing the result of the sort into

the key store

groups if set to True and if get contains at least two

elements, sort will return a list of tuples, each containing the values fetched from the arguments to get.

spop(name)

Remove and return a random member of set name

srandmember(name, number=None)

If number is None, returns a random member of set name.

If number is supplied, returns a list of number random memebers of set name. Note this is only available when running Redis 2.6+.

srem(name, *values)

Remove values from set name

sscan(name, cursor=0, match=None, count=None)

Incrementally return lists of elements in a set. Also return a cursor indicating the scan position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

sscan_iter(name, match=None, count=None)

Make an iterator using the SSCAN command so that the client doesn’t need to remember the cursor position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

strlen(name)

Return the number of bytes stored in the value of name

substr(name, start, end=-1)

Return a substring of the string at key name. start and end are 0-based integers specifying the portion of the string to return.

sunion(keys, *args)

Return the union of sets specified by keys

sunionstore(dest, keys, *args)

Store the union of sets specified by keys into a new set named dest. Returns the number of keys in the new set.

time()

Returns the server time as a 2-item tuple of ints: (seconds since epoch, microseconds into this second).

transaction(func, *watches, **kwargs)

Convenience method for executing the callable func as a transaction while watching all keys specified in watches. The ‘func’ callable should expect a single argument which is a Pipeline object.

ttl(name)

Returns the number of seconds until the key name will expire

type(name)

Returns the type of key name

unwatch()

Unwatches the value at key name, or None of the key doesn’t exist

watch(*names)

Watches the values at keys names, or None if the key doesn’t exist

zadd(name, *args, **kwargs)

Set any number of score, element-name pairs to the key name. Pairs can be specified in two ways:

As *args, in the form of: score1, name1, score2, name2, ... or as **kwargs, in the form of: name1=score1, name2=score2, ...

The following example would add four values to the ‘my-key’ key: redis.zadd(‘my-key’, 1.1, ‘name1’, 2.2, ‘name2’, name3=3.3, name4=4.4)

zcard(name)

Return the number of elements in the sorted set name

zcount(name, min, max)

Returns the number of elements in the sorted set at key name with a score between min and max.

zincrby(name, value, amount=1)

Increment the score of value in sorted set name by amount

zinterstore(dest, keys, aggregate=None)

Intersect multiple sorted sets specified by keys into a new sorted set, dest. Scores in the destination will be aggregated based on the aggregate, or SUM if none is provided.

zlexcount(name, min, max)

Return the number of items in the sorted set name between the lexicographical range min and max.

zrange(name, start, end, desc=False, withscores=False, score_cast_func=<type 'float'>)

Return a range of values from sorted set name between start and end sorted in ascending order.

start and end can be negative, indicating the end of the range.

desc a boolean indicating whether to sort the results descendingly

withscores indicates to return the scores along with the values. The return type is a list of (value, score) pairs

score_cast_func a callable used to cast the score return value

zrangebylex(name, min, max, start=None, num=None)

Return the lexicographical range of values from sorted set name between min and max.

If start and num are specified, then return a slice of the range.

zrangebyscore(name, min, max, start=None, num=None, withscores=False, score_cast_func=<type 'float'>)

Return a range of values from the sorted set name with scores between min and max.

If start and num are specified, then return a slice of the range.

withscores indicates to return the scores along with the values. The return type is a list of (value, score) pairs

score_cast_func` a callable used to cast the score return value

zrank(name, value)

Returns a 0-based value indicating the rank of value in sorted set name

zrem(name, *values)

Remove member values from sorted set name

zremrangebylex(name, min, max)

Remove all elements in the sorted set name between the lexicographical range specified by min and max.

Returns the number of elements removed.

zremrangebyrank(name, min, max)

Remove all elements in the sorted set name with ranks between min and max. Values are 0-based, ordered from smallest score to largest. Values can be negative indicating the highest scores. Returns the number of elements removed

zremrangebyscore(name, min, max)

Remove all elements in the sorted set name with scores between min and max. Returns the number of elements removed.

zrevrange(name, start, end, withscores=False, score_cast_func=<type 'float'>)

Return a range of values from sorted set name between start and end sorted in descending order.

start and end can be negative, indicating the end of the range.

withscores indicates to return the scores along with the values The return type is a list of (value, score) pairs

score_cast_func a callable used to cast the score return value

zrevrangebyscore(name, max, min, start=None, num=None, withscores=False, score_cast_func=<type 'float'>)

Return a range of values from the sorted set name with scores between min and max in descending order.

If start and num are specified, then return a slice of the range.

withscores indicates to return the scores along with the values. The return type is a list of (value, score) pairs

score_cast_func a callable used to cast the score return value

zrevrank(name, value)

Returns a 0-based value indicating the descending rank of value in sorted set name

zscan(name, cursor=0, match=None, count=None, score_cast_func=<type 'float'>)

Incrementally return lists of elements in a sorted set. Also return a cursor indicating the scan position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

score_cast_func a callable used to cast the score return value

zscan_iter(name, match=None, count=None, score_cast_func=<type 'float'>)

Make an iterator using the ZSCAN command so that the client doesn’t need to remember the cursor position.

match allows for filtering the keys by pattern

count allows for hint the minimum number of returns

score_cast_func a callable used to cast the score return value

zscore(name, value)

Return the score of element value in sorted set name

zunionstore(dest, keys, aggregate=None)

Union multiple sorted sets specified by keys into a new sorted set, dest. Scores in the destination will be aggregated based on the aggregate, or SUM if none is provided.