Python traverses the database and obtains the key value

Python traverses the database and obtains the key value

This article will share with you how to use Python to traverse the database and obtain the key value, mainly through the for loop. for more information, see.

Traverse the Redis database with keys stored in key-value mode in the format of PREFIX _ * and print their values.

SCAN is used for traversal, because keys prefix _ * may cause Redis to block for a long time.

Query uses pipeline to reduce interaction and improve efficiency.

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Import redis Import hiredis   Pool = redis. ConnectionPool (host = '127. 0.0.1 ', port = 127, db = 0) R = redis. Redis (connection_pool = pool)   Pipe = r. pipeline () Pipe_size = 100000   Len = 0 Key_list = [] For key in r. scan_iter (match = 'prefix _ * ', count = 100000 ): Key_list.append (key) Pipe. get (key) If len <pipe_size: Len + = 1 Else: For (k, v) in zip (key_list, pipe.exe cute ()): Print k, v Len = 0 Key_list = []   For (k, v) in zip (key_list, pipe.exe cute ()): Print k, v

Attach the code for other web pages. For more information, see

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# Filename itertaorfilefolder Import OS Import OS. path   FilePath = raw_input ('enter filepath :')   # Traversing folders # Three parameters: return 1. parent directory 2. All folder names (excluding paths) 3. All file names For parent, dirnames, filenames in OS. walk (filePath ): # Output Folder Information For dirname in dirnames: Print 'parent is: '+ parent Print 'dirname is '+ dirname # Output file information For filename in filenames: Print 'parent is: '+ parent Print 'filename is: '+ filename # Output file path information CurrentPath = OS. path. join (parent, filename) Print 'the fulll name of the file is: '+ currentPath Filesize = OS. path. getsize (currentPath)/1024/1024 Print 'The file size is: %. 3f mb' % (filesize) # Delete files larger than 50 MB If filesize> 50: Delete = raw_input ('Are you sure to delete? ') If delete = 'yes ': OS. remove (currentPath)

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