Convert logging doctest examples to testable snippets.

docs/index.rst

@@ -109,6 +109,7 @@
   logging-entries
   logging-metric
   logging-sink
+  logging-stdlib-usage
   logging-handlers
   logging-transports-sync
   logging-transports-thread

docs/logging-stdlib-usage.rst

@@ -0,0 +1,71 @@
+Integration with Python logging module
+--------------------------------------
+
+
+It's possible to tie the Python :mod:`logging` module directly into Google Cloud Logging. To use it,
+create a :class:`CloudLoggingHandler <google.cloud.logging.CloudLoggingHandler>` instance from your
+Logging client.
+
+.. code-block:: python
+
+    >>> import logging
+    >>> import google.cloud.logging # Don't conflict with standard logging
+    >>> from google.cloud.logging.handlers import CloudLoggingHandler
+    >>> client = google.cloud.logging.Client()
+    >>> handler = CloudLoggingHandler(client)
+    >>> cloud_logger = logging.getLogger('cloudLogger')
+    >>> cloud_logger.setLevel(logging.INFO) # defaults to WARN
+    >>> cloud_logger.addHandler(handler)
+    >>> cloud_logger.error('bad news')
+
+.. note::
+
+    This handler by default uses an asynchronous transport that sends log entries on a background
+     thread. However, the API call will still be made in the same process. For other transport
+     options, see the transports section.
+
+All logs will go to a single custom log, which defaults to "python". The name of the Python
+logger will be included in the structured log entry under the "python_logger" field. You can
+change it by providing a name to the handler:
+
+.. code-block:: python
+
+    >>> handler = CloudLoggingHandler(client, name="mycustomlog")
+
+It is also possible to attach the handler to the root Python logger, so that for example a plain
+`logging.warn` call would be sent to Cloud Logging, as well as any other loggers created. However,
+you must avoid infinite recursion from the logging calls the client itself makes. A helper
+method :meth:`setup_logging <google.cloud.logging.handlers.setup_logging>` is provided to configure
+this automatically:
+
+.. code-block:: python
+
+    >>> import logging
+    >>> import google.cloud.logging # Don't conflict with standard logging
+    >>> from google.cloud.logging.handlers import CloudLoggingHandler, setup_logging
+    >>> client = google.cloud.logging.Client()
+    >>> handler = CloudLoggingHandler(client)
+    >>> logging.getLogger().setLevel(logging.INFO) # defaults to WARN
+    >>> setup_logging(handler)
+    >>> logging.error('bad news')
+
+You can also exclude certain loggers:
+
+.. code-block:: python
+
+   >>> setup_logging(handler, excluded_loggers=('werkzeug',)))
+
+
+
+Python logging handler transports
+==================================
+
+The Python logging handler can use different transports. The default is
+:class:`google.cloud.logging.handlers.BackgroundThreadTransport`.
+
+ 1. :class:`google.cloud.logging.handlers.BackgroundThreadTransport` this is the default. It writes
+ entries on a background :class:`python.threading.Thread`.
+
+ 1. :class:`google.cloud.logging.handlers.SyncTransport` this handler does a direct API call on each
+ logging statement to write the entry.
+