Merge pull request #305 from IBM/improve-python-structured-logging

Improve python structured logging sample

Author: reggeenr

logging/python-structured/main.py

@@ -1,12 +1,13 @@
-
-from loguru import logger
 import sys
 import json
 import traceback
 
-# This simple Code Engine job demonstrates how to write structured log lines 
+from loguru import logger
+
+# This simple Code Engine job demonstrates how to write structured log lines
 # using the logging library loguru (https://github.com/Delgan/loguru)
 
+
 # Define a custom JSON sink
 def json_sink(message):
     record = message.record
@@ -35,28 +36,22 @@ def json_sink(message):
     sys.stdout.flush()
 
 
-# Remove default handler (which includes timestamp, etc.) and add our custom sink
-logger.remove()
-logger.add(json_sink, level="DEBUG")  # lowest level you want to capture
-
-
-if __name__ == '__main__':
-    
+def main():
     # expect to be rendered as INFO level log message
-    logger.info("This is a structured log message");
+    logger.info("This is a structured log message")
 
     # expect to be rendered as DEBUG level log message
-    logger.debug("This is a structured log message");
+    logger.debug("This is a structured log message")
 
     # expect to be rendered as WARN level log message
-    logger.warning("This is a structured log message");
+    logger.warning("This is a structured log message")
 
     # expect to be rendered as ERROR level log message
-    logger.error("This is a structured log message");
+    logger.error("This is a structured log message")
 
     # Expect to be rendered as DEBUG level log message. The extra key is available as a searchable, filterable field
     logger.bind(extra_key="extra_value").debug("A structured log entry that contains an extra key")
-    
+
     # Expect to be rendered as INFO level log message. The additional JSON struct is available as a searchable, filterable fields
     logger.bind(
         requestId="some-request-id",
@@ -65,7 +60,6 @@ def json_sink(message):
         metadata={"foo": "bar"},
     ).info("A structured log entry that carries a ton of additional fields")
 
-    
     # Multi-line example. Expect to be rendered in a single log message
     logger.info(
         "Multi-line log sample:\n"
@@ -75,13 +69,23 @@ def json_sink(message):
         "Line 4: entering main loop\n"
         "End of sample"
     )
-    
+
     # Error logging. The error stack trace is rendered in a single log message (see field stack)
     try:
         raise RuntimeError("boom!")
     except Exception:
         # logger.exception() automatically attaches the current exception info
         logger.exception("An error occurred")
 
+    # this will be caught by loguru's logger.catch context
+    import nonexistentmodule
+
+
+if __name__ == '__main__':
+    # Remove default handler (which includes timestamp, etc.) and add our custom sink
+    logger.remove()
+    logger.add(json_sink, level="DEBUG")  # lowest level you want to capture
 
-    
+    # Catch any uncaught errors and properly log them
+    with logger.catch():
+        main()