Add types to logging.py (#1226)

* Add types to logging.py

Signed-off-by: Michael Carlstrom <[email protected]>

* Using LoggingSeverity Enum over int

Signed-off-by: Michael Carlstrom <[email protected]>

* Add type Union of int and LoggingSeverity because set_logger_level seems like it could take ints

Signed-off-by: Michael Carlstrom <[email protected]>

* Switch to Union over | for python 3.8 support

Signed-off-by: Michael Carlstrom <[email protected]>

* add return types

Signed-off-by: Michael Carlstrom <[email protected]>

---------

Signed-off-by: Michael Carlstrom <[email protected]>

rclpy/rclpy/logging.py

@@ -14,51 +14,53 @@
 
 
 from pathlib import Path
+from typing import Union
 
 from rclpy.impl.implementation_singleton import rclpy_implementation as _rclpy
 from rclpy.impl.logging_severity import LoggingSeverity
-import rclpy.impl.rcutils_logger
+from rclpy.impl.rcutils_logger import RcutilsLogger
 
 
-_root_logger = rclpy.impl.rcutils_logger.RcutilsLogger()
+_root_logger = RcutilsLogger()
 
 
-def get_logger(name):
+def get_logger(name: str) -> RcutilsLogger:
     if not name:
         raise ValueError('Logger name must not be empty.')
     return _root_logger.get_child(name)
 
 
-def initialize():
-    return _rclpy.rclpy_logging_initialize()
+def initialize() -> None:
+    _rclpy.rclpy_logging_initialize()
 
 
-def shutdown():
-    return _rclpy.rclpy_logging_shutdown()
+def shutdown() -> None:
+    _rclpy.rclpy_logging_shutdown()
 
 
-def clear_config():
+def clear_config() -> None:
     """Clear the configuration of the logging system, e.g. logger levels."""
     shutdown()
     initialize()
 
 
-def set_logger_level(name, level, detailed_error=False):
+def set_logger_level(name: str, level: Union[int, LoggingSeverity],
+                     detailed_error: bool = False) -> None:
     level = LoggingSeverity(level)
-    return _rclpy.rclpy_logging_set_logger_level(name, level, detailed_error)
+    _rclpy.rclpy_logging_set_logger_level(name, level, detailed_error)
 
 
-def get_logger_effective_level(name):
+def get_logger_effective_level(name: str) -> LoggingSeverity:
     logger_level = _rclpy.rclpy_logging_get_logger_effective_level(name)
     return LoggingSeverity(logger_level)
 
 
-def get_logger_level(name):
+def get_logger_level(name: str) -> LoggingSeverity:
     logger_level = _rclpy.rclpy_logging_get_logger_level(name)
     return LoggingSeverity(logger_level)
 
 
-def get_logging_severity_from_string(log_severity):
+def get_logging_severity_from_string(log_severity: str) -> LoggingSeverity:
     return LoggingSeverity(
         _rclpy.rclpy_logging_severity_level_from_string(log_severity))