Merge pull request #273 from xj9/logging

Real logging, please incorporate into new and existing code.

src/debug.py

@@ -0,0 +1,65 @@
+# -*- coding: utf-8 -*-
+'''
+Logging and debuging facility
+=============================
+
+Levels:
+    DEBUG       Detailed information, typically of interest only when diagnosing problems.
+    INFO        Confirmation that things are working as expected.
+    WARNING     An indication that something unexpected happened, or indicative of some problem in the
+                near future (e.g. ‘disk space low’). The software is still working as expected.
+    ERROR       Due to a more serious problem, the software has not been able to perform some function.
+    CRITICAL    A serious error, indicating that the program itself may be unable to continue running.
+
+There are three loggers: `console_only`, `file_only` and `both`.
+
+Use: `from debug import logger` to import this facility into whatever module you wish to log messages from.
+     Logging is thread-safe so you don't have to worry about locks, just import and log.
+'''
+import logging
+import logging.config
+
+# TODO(xj9): Get from a config file.
+log_level = 'DEBUG'
+
+logging.config.dictConfig({
+    'version': 1,
+    'formatters': {
+        'default': {
+            'format': '%(asctime)s - %(levelname)s - %(message)s',
+        },
+    },
+    'handlers': {
+        'console': {
+            'class': 'logging.StreamHandler',
+            'formatter': 'default',
+            'level': log_level,
+            'stream': 'ext://sys.stdout'
+        },
+        'file': {
+            'class': 'logging.handlers.RotatingFileHandler',
+            'formatter': 'default',
+            'level': log_level,
+            'filename': 'bm.log',
+            'maxBytes': 1024,
+            'backupCount': 0,
+        }
+    },
+    'loggers': {
+        'console_only': {
+            'handlers': ['console'],
+        },
+        'file_only': {
+            'handlers': ['file'],
+        },
+        'both': {
+            'handlers': ['console', 'file'],
+        },
+    },
+    'root': {
+        'level': log_level,
+        'handlers': ['console'],
+    },
+})
+# TODO (xj9): Get from a config file.
+logger = logging.getLogger('console_only')