sider.list — List objects

See also

Redis Data Types
The Redis documentation that explains about its data types: strings, lists, sets, sorted sets and hashes.
class sider.list.List(session, key, value_type=<class 'sider.types.ByteString'>)

The Python-side representaion of Redis list value. It behaves alike built-in Python list object. More exactly, it implements collections.MutableSequence protocol.

Mappings of Redis commands–List methods
Redis commands List methods
LLEN len() (List.__len__())
LPUSH List.insert()
LPUSHX N/A
LPOP List.pop()
RPUSH List.append(), List.extend()
RPUSHX N/A
RPOP List.pop()
RPOPLPUSH N/A
LINDEX List.__getitem__(),
LINSERT N/A
LRANGE iter() (List.__iter__()), List.__getitem__(),
LREM N/A
LTRIM del (List.__delitem__())
DEL del (List.__delitem__())
LSET = (List.__setitem__())
BLPOP N/A
BRPOP N/A
BRPOPLPUSH N/A
append(*args, **kwargs)

Inserts the value at the tail of the list.

Parameters:value – an value to insert
extend(iterable)

Extends the list with the iterable.

Parameters:iterable (collections.Iterable) – an iterable object that extend the list with
Raises:exceptions.TypeError – if the given iterable is not iterable

Warning

Appending multiple values is supported since Redis 2.4.0. This may send RPUSH multiple times in a transaction if Redis version is not 2.4.0 nor higher.

insert(index, value)

Inserts the value right after the offset index.

Parameters:
  • index (numbers.Integral) – the offset of the next before the place where value would be inserted to
  • value – the value to insert
Raises:

exceptions.TypeError – if the given index is not an integer

Warning

Redis does not provide any primitive operations for random insertion. You only can prepend or append a value into lists. If index is 0 it’ll send LPUSH command, but otherwise it inefficiently LRANGE the whole list to manipulate it in offline, and then DEL the key so that empty the whole list, and then RPUSH the whole result again. Moreover all the commands execute in a transaction.

So you should not treat this method as the same method of Python built-in list object. It is just for being compatible to collections.MutableSequence protocol.

If it faced the case, it also will warn you PerformanceWarning.

pop(index=-1, _stacklevel=1)

Removes and returns an item at index. Negative index means len(list) + index (counts from the last).

Parameters:
  • index (numbers.Integral) – an index of an item to remove and return
  • _stacklevel (numbers.Integral) – internal use only. base stacklevel for warning. default is 1
Returns:

the removed element
Raises:

Warning

Redis doesn’t offer any primitive operations for random deletion. You can pop only the last or the first. Other middle elements cannot be popped in a command, so it emulates the operation inefficiently.

Internal emulation routine to pop an other index than -1 or 0 consists of three commands in a transaction:

  • LINDEX
  • LTRIM
  • RPUSH (In worst case, this command would be sent N times where N is the cardinality of elements placed after popped index. Because multiple operands for RPUSH was supported since Redis 2.4.0.)

So you should not treat this method as the same method of Python built-in list object. It is just for being compatible to collections.MutableSequence protocol.

If it faced the case, it also will warn you PerformanceWarning.

value_type = None

(sider.types.Bulk) The type of list values.