Cache.iterkeys()

Iterate over keys in sorted order, optionally only those starting with prefix.

Usage

Source

Cache.iterkeys(
    *,
    prefix=None,
    reverse=False,
)

A prefix is an indexed range scan, so it costs time in proportion to the matches, not the size of the cache. Keys are fetched a page at a time with no lock held in between, so deleting keys while iterating is safe. Expired entries not yet removed are included. Like a generator, an iterator serves one thread at a time: next() raises ValueError while another thread is inside it.

Parameters

prefix: str | None = None

Only yield keys that start with this string.

reverse: bool = False

Yield keys in descending order.

Returns

Iterator[str]

An iterator of keys.

Examples

for key in cache.iterkeys(prefix='user:42:'):   # an indexed range scan, sorted
    cache.delete(key)
newest_first = cache.iterkeys(reverse=True)