How to iterate over all keys using the scan command

By using the scan command, we can iterate over all keys in Redis by following the steps below: The initial cursor is set to 0. Loops the SCAN 0 command to get the result set and a new cursor. The number of keys contained in each result set can be specified by the COUNT option. Use the new cursor as the first parameter of the SCAN command to get the next result set. Continue looping until the returned cursor is 0, indicating that there are no more results.

How to iterate over all keys using scan command

The scan command can be used to iterate over all keys in Redis. The syntax is as follows:

 <code>SCAN cursor [MATCH pattern] [COUNT count]</code>

parameter:

• cursor : cursor returned by the last scan command. It should be 0 for the first call.
• MATCH pattern : Can be used to filter keys to iterate. When specifying a pattern, only the keys that match the pattern will be returned.
• COUNT count : Specifies the number of keys to include in each return result. The default value is 10.

usage:

To iterate over all keys, you can use the following command:

 <code>SCAN 0</code>

This will return the first result set and a new cursor. A cursor is the offset of the next result set every time scan command is called.

To get the next result set, re-call the scan command with the new cursor as the first parameter:

 <code>SCAN cursor</code>

Continue this process until the returned cursor is 0. This means there are no more results to return.

Example:

The following example demonstrates how to use the scan command to get all keys:

 <code class="python">import redis r = redis.Redis() cursor = 0 while cursor != 0: cursor, keys = r.scan(cursor=cursor) for key in keys: print(key)</code>

Output:

 <code>key1 key2 key3</code>

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