logger.json

{
    "version": 1,
    "formatters": {
        "default": {
            "format": "default %(asctime)s %(levelname)s %(message)s"
        },

        "forA": {
            "format": "forA %(asctime)s %(levelname)s %(message)s"
        },

        "forB": {
            "format": "forB %(asctime)s %(levelname)s %(message)s"
        }
    },

    "handlers": {
      "info_file_handler": {
          "class": "logging.handlers.RotatingFileHandler",
          "level": "INFO",
          "formatter": "default",
          "filename": "info.log",
          "maxBytes": 10485760,
          "backupCount": 20,
          "encoding": "utf8"
      },

        "forA": {
          "class": "logging.handlers.RotatingFileHandler",
          "level": "INFO",
          "formatter": "forA",
          "filename": "info.log",
          "maxBytes": 10485760,
          "backupCount": 20,
          "encoding": "utf8"
      },

        "forB": {
          "class": "logging.handlers.RotatingFileHandler",
          "level": "INFO",
          "formatter": "forB",
          "filename": "info.log",
          "maxBytes": 10485760,
          "backupCount": 20,
          "encoding": "utf8"
      }

    },

    "loggers": {
        "__main__": {
            "level": "INFO",
            "handlers": ["info_file_handler"],
            "propagate": false
        },

        "__main__.A": {
            "level": "INFO",
            "handlers": ["forA"],
            "propagate": false
        },

        "__main__.B": {
            "level": "INFO",
            "handlers": ["forB"],
            "propagate": false
        }
    },

    "root": {
        "level": "INFO"
    }
}