Merge pull request #136 from cs50/logger

configure root logger

Author: Kareem Zidane

src/cs50/cs50.py

@@ -1,6 +1,7 @@
 from __future__ import print_function
 
 import inspect
+import logging
 import os
 import re
 import sys
@@ -11,6 +12,32 @@
 from traceback import format_exception
 
 
+# Configure default logging handler and formatter
+# Prevent flask, werkzeug, etc from adding default handler
+logging.basicConfig(format="%(levelname)s: %(message)s", level=logging.DEBUG)
+
+try:
+    # Patch formatException
+    logging.root.handlers[0].formatter.formatException = lambda exc_info: _formatException(*exc_info)
+except IndexError:
+    pass
+
+# Configure cs50 logger
+_logger = logging.getLogger("cs50")
+_logger.setLevel(logging.DEBUG)
+
+# Log messages once
+_logger.propagate = False
+
+handler = logging.StreamHandler()
+handler.setLevel(logging.DEBUG)
+
+formatter = logging.Formatter("%(levelname)s: %(message)s")
+formatter.formatException = lambda exc_info: _formatException(*exc_info)
+handler.setFormatter(formatter)
+_logger.addHandler(handler)
+
+
 class _flushfile():
     """
     Disable buffering for standard output and standard error.

src/cs50/flask.py

@@ -12,8 +12,6 @@ def _wrap_flask(f):
     if f.__version__ < StrictVersion("1.0"):
         return
 
-    f.logging.default_handler.formatter.formatException = lambda exc_info: _formatException(*exc_info)
-
     if os.getenv("CS50_IDE_TYPE") == "online":
         from werkzeug.middleware.proxy_fix import ProxyFix
         _flask_init_before = f.Flask.__init__

src/cs50/sql.py

@@ -45,9 +45,6 @@ def __init__(self, url, **kwargs):
         import sqlalchemy
         import sqlite3
 
-        # Get logger
-        self._logger = logging.getLogger("cs50")
-
         # Require that file already exist for SQLite
         matches = re.search(r"^sqlite:///(.+)$", url)
         if matches:
@@ -59,6 +56,8 @@ def __init__(self, url, **kwargs):
         # Create engine, disabling SQLAlchemy's own autocommit mode, raising exception if back end's module not installed
         self._engine = sqlalchemy.create_engine(url, **kwargs).execution_options(autocommit=False)
 
+        self._logger = logging.getLogger("cs50")
+
         # Listener for connections
         def connect(dbapi_connection, connection_record):
 
@@ -78,13 +77,11 @@ def connect(dbapi_connection, connection_record):
         # Register listener
         sqlalchemy.event.listen(self._engine, "connect", connect)
 
-        # Log statements to standard error
-        logging.basicConfig(level=logging.DEBUG)
 
         # Test database
+        disabled = self._logger.disabled
+        self._logger.disabled = True
         try:
-            disabled = self._logger.disabled
-            self._logger.disabled = True
             self.execute("SELECT 1")
         except sqlalchemy.exc.OperationalError as e:
             e = RuntimeError(_parse_exception(e))