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#-*-coding: utf-8-*-# knowledge point: reflection # imports the module in the form of a string, which is reflection # and executes the function in the form of a string # first look at the simple small particle temp = 'mysql' # this string is the name of the module (that is, mysql.py or sqlserver.py The suffix name is not required) func = 'count' # this string is the name of the function (that is, the function count in mysql.py/sqlserver.py) model = _ _ import__ (temp) # import the module in the form of a string # the first method of the function in the execution module print model.count () # the function in the execution module the second method Function = getattr (model Func) # execute the function print Function () as a string below simulate a database connection of small particles # prepare the following two files' mysql.py file to simulate connection to the mysql database Normal connection returns "- *-coding: utf-8-*-def count (): return 1sqlserver.py file simulates connecting to sqlserver database, and normal connection returns"-*-coding: utf-8-*-def count (): return 2 subscription. # Note: mysql.py and sqlserver.py files can be defined by themselves. Here is the statement def db_count (db_name) that is not actually connected to the database: temp = db_name # module name (that is, mysql or sqlserver) func = 'count' # function (that is, function count in mysql.py/sqlserver.py) model = _ _ import__ (temp) Function = getattr (model) Func) # execute the function return Function () as a string # currently simulates the default connection to the sqlserver database status = db_count ('sqlserver') # check the status of the connection sqlserver (normal state: 2) If you cannot connect, switch to mysqlif status! = 2: status = db_count ('mysql') print' has been switched to mysql, connection ID:%d'% statuselse: print 'sqlserver connection is normal, connection ID:%d'% status# test action: # 1, the count return value in sqlserver.py can be modified to 3

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