try:
    #Connexion à la base MySQL
     if (base1 == "mysql") or (base2 == "mysql"):
    cnx = mysql.connector.connect(user=user_mysql, password=password_mysql,host=host_mysql,database=database_mysql)
    #Connexion à la base MSSQL
     if (base1 == "mssql") or (base2 == "mssql"):
      conn = pymssql.connect(server=host_mssql, user=user_mssql, password=password_mssql, database=database_mssql)
     else:
      print "parametres incorrecte !!"
except IndexError:
         print("manque de parametre !! il faut saisir les deux SGBD à comparer !!")