Reference¶
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class
pylibmc.
Client
(servers[, binary=False, behaviors=None])¶ Interface to a set of memcached servers.
servers is a sequence of strings specifying the servers to use.
binary specifies whether or not to use the binary protocol to talk to the memcached servers.
behaviors, if given, is passed to
Client.set_behaviors()
after initialization.Supported transport mechanisms are TCP, UDP and UNIX domain sockets. The default transport type is TCP.
To specify UDP, the server address should be prefixed with
"udp:"
, as in"udp:127.0.0.1"
.To specify UNIX domain socket, the server address must start with a slash, as in
"/run/foo.sock"
.Mixing transport types is prohibited by
pylibmc
as this is not supported by libmemcached.-
clone
() → clone¶ Clone client, making new connections as necessary.
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get
(key) → value¶ Get key if it exists, otherwise
None
.
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get_multi
(keys[, key_prefix=None]) → values¶ Get each of the keys in sequence keys.
If key_prefix is given, specifies a string to prefix each of the values in keys with.
Returns a mapping of each unprefixed key to its corresponding value in memcached. If a key doesn’t exist, no corresponding key is set in the returned mapping.
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set
(key, value[, time=0, min_compress_len=0, compress_level=-1]) → success¶ Set key to value.
Parameters: - key – Key to use
- value – Value to set
- time – Time until expiry
- min_compress_len – Minimum length before compression is triggered
If time is given, it specifies the number of seconds until key will expire. Default behavior is to never expire (equivalent of specifying
0
).If min_compress_len is given, it specifies the maximum number of actual bytes stored in memcached before compression is used. Default behavior is to never compress (which is what
0
means). See Compression.If compress_level is given, it specifies the compression level for the data. It accepts the same values as the
zlib
family, for which zlib.Z_BEST_SPEED and zlib.Z_BEST_COMPRESSION are commonly used constants. It accepts values between [0, 9] inclusively.
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set_multi
(mapping[, time=0, key_prefix=None, min_compress_len, compress_level]) → failed_keys¶ Set multiple keys as given by mapping.
If key_prefix is specified, each of the keys in mapping is prepended with this value.
Returns a list of keys which were not set for one reason or another, without their optional key prefix.
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add
(key, value[, time, min_compress_len, compress_level]) → success¶ Sets key if it does not exist.
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replace
(key, value[, time, min_compress_len, compress_level]) → success¶ Sets key only if it already exists.
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append
(key, value) → success¶ Append value to key (i.e.,
m[k] = m[k] + v
).Note
Uses memcached’s appending support, and therefore should never be used on keys which may be compressed or non-string values.
-
prepend
(key, value) → success¶ Prepend value to key (i.e.,
m[k] = v + m[k]
).Note
Uses memcached’s prepending support, and therefore should never be used on keys which may be compressed or non-string values.
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incr
(key[, delta=1]) → value¶ Increment value at key by delta.
Returns the new value for key, after incrementing.
Works for both strings and integer types.
Note
There is currently no way to set a default for key when incrementing.
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decr
(key[, delta=1]) → value¶ Decrement value at key by delta.
Returns the new value for key, after decrementing.
Works for both strings and integer types, but will never decrement below zero.
Note
There is currently no way to set a default for key when decrementing.
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gets
(key) -> (value, cas_id)¶ Get key and its compare-and-swap ID if it exists, otherwise
(None, None)
.The so-called CAS token or ID is used with
cas()
to update a value with the guarantee that no other value was written in between.
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cas
(key, value, cas[, time=0]) → swapped¶ Set key to value if key CAS token is cas.
Parameters: - key – Key to use
- value – Value to set
- cas – Compare-and-swap token from
gets()
- time – Time until expiry
If time is given, it specifies the number of seconds until key will expire. Default behavior is to never expire (equivalent of specifying
0
).
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delete
(key[, time=0]) → deleted¶ Delete key if it exists.
If time is non-zero, this is equivalent of setting an expiry time for a key, i.e., the key will cease to exist after that many seconds.
Returns
True
if the key was deleted,False
otherwise (as is the case if it wasn’t set in the first place.)Note
Some versions of libmemcached are unable to set time for a delete. This is true of versions up until at least 0.38.
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delete_multi
(keys[, time=0, key_prefix=None]) → deleted¶ Delete each of key in the sequence keys.
Parameters: - keys – Sequence of keys to delete
- time – Number of seconds until the keys are deleted
- key_prefix – Prefix for the keys to delete
If time is zero, the keys are deleted immediately.
Returns
True
if all keys were successfully deleted,False
otherwise (as is the case if it wasn’t set in the first place.)
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touch
(key, time) → touched¶ Touch a given key and increase it’s expiry time by time seconds.
Parameters: - key – Key to touch
- time – Number of seconds until the key expires.
Returns
True
if the key was successfully touched.False
if the key did not exist.
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disconnect_all
()¶ Disconnect from all servers and reset internal state.
Exposed mainly for compatibility with python-memcached, as there really is no logical reason to do this.
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flush_all
() → success¶ Flush all data from all servers.
Note
This clears the specified memcacheds fully and entirely.
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get_stats
() → [(name, stats), ...]¶ Retrieve statistics from each of the connected memcached instances.
Returns a list of two-tuples of the format
(name, stats)
.stats is a mapping of statistics item names to their values. Whether or not a key exists depends on the version of libmemcached and memcached used.
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