Refactor logger setup with optional name and level

settings/logger.py

@@ -1,13 +1,51 @@
 import logging
 import sys
+from typing import Optional
 
 
-def setup_logger():
-    logger = logging.getLogger()
-    logger.setLevel(logging.INFO)
+def setup_logger(name: Optional[str] = None, level: int = logging.INFO) -> logging.Logger:
+    """
+    Sets up a basic logger for the application or a specific module.
 
-    handler = logging.StreamHandler(sys.stdout)
-    handler.setLevel(logging.INFO)
-    formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
-    handler.setFormatter(formatter)
-    logger.addHandler(handler)
+    This function ensures that a StreamHandler is only added once and directs
+    log output to sys.stderr for better separation from normal program output.
+
+    Args:
+        name: The name of the logger to configure (e.g., 'app.module'). 
+              If None, configures the root logger.
+        level: The minimum logging level to output.
+
+    Returns:
+        The configured logging.Logger instance.
+    """
+    # 1. Get the logger instance.
+    logger = logging.getLogger(name)
+    logger.setLevel(level)
+
+    # 2. Check if a StreamHandler is already present to prevent duplicate logs.
+    if not logger.handlers:
+        # Create a StreamHandler that directs logs to standard error.
+        handler = logging.StreamHandler(sys.stderr)
+        handler.setLevel(level)
+
+        # Define a consistent format for log messages.
+        formatter = logging.Formatter(
+            "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+        )
+        handler.setFormatter(formatter)
+
+        # Add the handler to the logger.
+        logger.addHandler(handler)
+
+    return logger
+
+# Example Usage (Not part of the optimized function, for illustration only):
+if __name__ == "__main__":
+    # Configure the root logger
+    root_log = setup_logger()
+    root_log.info("This is an INFO message from the root logger.")
+
+    # Configure a specific module logger
+    module_log = setup_logger("database_module", logging.DEBUG)
+    module_log.debug("This is a DEBUG message from the module logger.")
+    module_log.error("This is an ERROR message from the module logger.")