why mysql workbench could not import pyodbc module (no replies)

thanks, when I try to migration from sqlserver to mysql using workbench
it failed

Error calling get_enum_options() for param dsn: error calling Python module function DbMssqlRE.getDataSourceNamesConnecting to Mssql@DRIVER=SQL Server;SERVER=localhost\MSSQLSERVER...
20:58:51 [ERR][ python]: error calling DbMssqlRE.connectTraceback

ImportError: No module named pyodbc

but, in fact, I already installed , why ?