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<H2><A NAME="SECTION0082920000000000000000"></A><A NAME="minimal-example"></A>
<BR>
6.29.2 Basic example 
</H2>

<P>

<span class="versionnote">Changed in version 2.4:
formerly <tt class="function">basicConfig</tt> did not take any keyword
arguments.</span>

<P>
The <tt class="module">logging</tt> package provides a lot of flexibility, and its
configuration can appear daunting.  This section demonstrates that simple
use of the logging package is possible.

<P>
The simplest example shows logging to the console:

<P>
<div class="verbatim"><pre>
import logging

logging.debug('A debug message')
logging.info('Some information')
logging.warning('A shot across the bows')
</pre></div>

<P>
If you run the above script, you'll see this:
<div class="verbatim"><pre>
WARNING:root:A shot across the bows
</pre></div>

<P>
Because no particular logger was specified, the system used the root logger.
The debug and info messages didn't appear because by default, the root
logger is configured to only handle messages with a severity of WARNING
or above. The message format is also a configuration default, as is the output
destination of the messages - <code>sys.stderr</code>. The severity level,
the message format and destination can be easily changed, as shown in
the example below:

<P>
<div class="verbatim"><pre>
import logging

logging.basicConfig(level=logging.DEBUG,
                    format='%(asctime)s %(levelname)s %(message)s',
                    filename='/tmp/myapp.log',
                    filemode='w')
logging.debug('A debug message')
logging.info('Some information')
logging.warning('A shot across the bows')
</pre></div>

<P>
The <tt class="method">basicConfig()</tt> method is used to change the configuration
defaults, which results in output (written to <code>/tmp/myapp.log</code>)
which should look something like the following:

<P>
<div class="verbatim"><pre>
2004-07-02 13:00:08,743 DEBUG A debug message
2004-07-02 13:00:08,743 INFO Some information
2004-07-02 13:00:08,743 WARNING A shot across the bows
</pre></div>

<P>
This time, all messages with a severity of DEBUG or above were handled,
and the format of the messages was also changed, and output went to the
specified file rather than the console.

<P>
Formatting uses standard Python string formatting - see section
<A href="typesseq-strings.html#typesseq-strings">2.3.6</A>. The format string takes the following
common specifiers. For a complete list of specifiers, consult the
<tt class="class">Formatter</tt> documentation.

<P>
<div class="center"><table class="realtable">
  <thead>
    <tr>
      <th class="left"  >Format</th>
      <th class="left"  >Description</th>
      </tr>
    </thead>
  <tbody>
    <tr><td class="left"   valign="baseline"><code>%(name)s</code></td>
        <td class="left"  >Name of the logger (logging channel).</td></tr>
    <tr><td class="left"   valign="baseline"><code>%(levelname)s</code></td>
        <td class="left"  >Text logging level for the message
                        (<code>'DEBUG'</code>, <code>'INFO'</code>,
                        <code>'WARNING'</code>, <code>'ERROR'</code>,
                        <code>'CRITICAL'</code>).</td></tr>
    <tr><td class="left"   valign="baseline"><code>%(asctime)s</code></td>
        <td class="left"  >Human-readable time when the <tt class="class">LogRecord</tt>
                        was created.  By default this is of the form
                        ``2003-07-08 16:49:45,896'' (the numbers after the
                        comma are millisecond portion of the time).</td></tr>
    <tr><td class="left"   valign="baseline"><code>%(message)s</code></td>
        <td class="left"  >The logged message.</td></tr></tbody>
</table></div>

<P>
To change the date/time format, you can pass an additional keyword parameter,
<var>datefmt</var>, as in the following:

<P>
<div class="verbatim"><pre>
import logging

logging.basicConfig(level=logging.DEBUG,
                    format='%(asctime)s %(levelname)-8s %(message)s',
                    datefmt='%a, %d %b %Y %H:%M:%S',
                    filename='/temp/myapp.log',
                    filemode='w')
logging.debug('A debug message')
logging.info('Some information')
logging.warning('A shot across the bows')
</pre></div>

<P>
which would result in output like

<P>
<div class="verbatim"><pre>
Fri, 02 Jul 2004 13:06:18 DEBUG    A debug message
Fri, 02 Jul 2004 13:06:18 INFO     Some information
Fri, 02 Jul 2004 13:06:18 WARNING  A shot across the bows
</pre></div>

<P>
The date format string follows the requirements of <tt class="function">strftime()</tt> -
see the documentation for the <tt class="module"><a href="module-time.html">time</a></tt> module.

<P>
If, instead of sending logging output to the console or a file, you'd rather
use a file-like object which you have created separately, you can pass it
to <tt class="function">basicConfig()</tt> using the <var>stream</var> keyword argument. Note
that if both <var>stream</var> and <var>filename</var> keyword arguments are passed,
the <var>stream</var> argument is ignored.

<P>
Of course, you can put variable information in your output. To do this,
simply have the message be a format string and pass in additional arguments
containing the variable information, as in the following example:

<P>
<div class="verbatim"><pre>
import logging

logging.basicConfig(level=logging.DEBUG,
                    format='%(asctime)s %(levelname)-8s %(message)s',
                    datefmt='%a, %d %b %Y %H:%M:%S',
                    filename='/temp/myapp.log',
                    filemode='w')
logging.error('Pack my box with %d dozen %s', 5, 'liquor jugs')
</pre></div>

<P>
which would result in

<P>
<div class="verbatim"><pre>
Wed, 21 Jul 2004 15:35:16 ERROR    Pack my box with 5 dozen liquor jugs
</pre></div>

<P>

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920dae64 AT	1	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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	54
	55	<H2><A NAME="SECTION0082920000000000000000"></A><A NAME="minimal-example"></A>
	56	<BR>
	57	6.29.2 Basic example
	58	</H2>
	59
	60	<P>
	61
	62	<span class="versionnote">Changed in version 2.4:
	63	formerly <tt class="function">basicConfig</tt> did not take any keyword
	64	arguments.</span>
65
66	<P>
67	The <tt class="module">logging</tt> package provides a lot of flexibility, and its
68	configuration can appear daunting. This section demonstrates that simple
69	use of the logging package is possible.
70
71	<P>
72	The simplest example shows logging to the console:
73
74	<P>
75	<div class="verbatim"><pre>
76	import logging
77
78	logging.debug('A debug message')
79	logging.info('Some information')
80	logging.warning('A shot across the bows')
81	</pre></div>
82
83	<P>
84	If you run the above script, you'll see this:
85	<div class="verbatim"><pre>
86	WARNING:root:A shot across the bows
87	</pre></div>
88
89	<P>
90	Because no particular logger was specified, the system used the root logger.
91	The debug and info messages didn't appear because by default, the root
92	logger is configured to only handle messages with a severity of WARNING
93	or above. The message format is also a configuration default, as is the output
94	destination of the messages - <code>sys.stderr</code>. The severity level,
95	the message format and destination can be easily changed, as shown in
96	the example below:
97
98	<P>
99	<div class="verbatim"><pre>
100	import logging
101
102	logging.basicConfig(level=logging.DEBUG,
103	format='%(asctime)s %(levelname)s %(message)s',
104	filename='/tmp/myapp.log',
105	filemode='w')
106	logging.debug('A debug message')
107	logging.info('Some information')
108	logging.warning('A shot across the bows')
109	</pre></div>
110
111	<P>
112	The <tt class="method">basicConfig()</tt> method is used to change the configuration
113	defaults, which results in output (written to <code>/tmp/myapp.log</code>)
114	which should look something like the following:
115
116	<P>
117	<div class="verbatim"><pre>
118	2004-07-02 13:00:08,743 DEBUG A debug message
119	2004-07-02 13:00:08,743 INFO Some information
120	2004-07-02 13:00:08,743 WARNING A shot across the bows
121	</pre></div>
122
123	<P>
124	This time, all messages with a severity of DEBUG or above were handled,
125	and the format of the messages was also changed, and output went to the
126	specified file rather than the console.
127
128	<P>
129	Formatting uses standard Python string formatting - see section
130	<A href="typesseq-strings.html#typesseq-strings">2.3.6</A>. The format string takes the following
131	common specifiers. For a complete list of specifiers, consult the
132	<tt class="class">Formatter</tt> documentation.
133
134	<P>
135	<div class="center"><table class="realtable">
136	<thead>
137	<tr>
138	<th class="left" >Format</th>
139	<th class="left" >Description</th>
140	</tr>
141	</thead>
142	<tbody>
143	<tr><td class="left" valign="baseline"><code>%(name)s</code></td>
144	<td class="left" >Name of the logger (logging channel).</td></tr>
145	<tr><td class="left" valign="baseline"><code>%(levelname)s</code></td>
146	<td class="left" >Text logging level for the message
147	(<code>'DEBUG'</code>, <code>'INFO'</code>,
148	<code>'WARNING'</code>, <code>'ERROR'</code>,
149	<code>'CRITICAL'</code>).</td></tr>
150	<tr><td class="left" valign="baseline"><code>%(asctime)s</code></td>
151	<td class="left" >Human-readable time when the <tt class="class">LogRecord</tt>
152	was created. By default this is of the form
153	``2003-07-08 16:49:45,896'' (the numbers after the
154	comma are millisecond portion of the time).</td></tr>
155	<tr><td class="left" valign="baseline"><code>%(message)s</code></td>
156	<td class="left" >The logged message.</td></tr></tbody>
157	</table></div>
158
159	<P>
160	To change the date/time format, you can pass an additional keyword parameter,
161	<var>datefmt</var>, as in the following:
162
163	<P>
164	<div class="verbatim"><pre>
165	import logging
166
167	logging.basicConfig(level=logging.DEBUG,
168	format='%(asctime)s %(levelname)-8s %(message)s',
169	datefmt='%a, %d %b %Y %H:%M:%S',
170	filename='/temp/myapp.log',
171	filemode='w')
172	logging.debug('A debug message')
173	logging.info('Some information')
174	logging.warning('A shot across the bows')
175	</pre></div>
176
177	<P>
178	which would result in output like
179
180	<P>
181	<div class="verbatim"><pre>
182	Fri, 02 Jul 2004 13:06:18 DEBUG A debug message
183	Fri, 02 Jul 2004 13:06:18 INFO Some information
184	Fri, 02 Jul 2004 13:06:18 WARNING A shot across the bows
185	</pre></div>
186
187	<P>
188	The date format string follows the requirements of <tt class="function">strftime()</tt> -
189	see the documentation for the <tt class="module"><a href="module-time.html">time</a></tt> module.
190
191	<P>
192	If, instead of sending logging output to the console or a file, you'd rather
193	use a file-like object which you have created separately, you can pass it
194	to <tt class="function">basicConfig()</tt> using the <var>stream</var> keyword argument. Note
195	that if both <var>stream</var> and <var>filename</var> keyword arguments are passed,
196	the <var>stream</var> argument is ignored.
197
198	<P>
199	Of course, you can put variable information in your output. To do this,
200	simply have the message be a format string and pass in additional arguments
201	containing the variable information, as in the following example:
202
203	<P>
204	<div class="verbatim"><pre>
205	import logging
206
207	logging.basicConfig(level=logging.DEBUG,
208	format='%(asctime)s %(levelname)-8s %(message)s',
209	datefmt='%a, %d %b %Y %H:%M:%S',
210	filename='/temp/myapp.log',
211	filemode='w')
212	logging.error('Pack my box with %d dozen %s', 5, 'liquor jugs')
213	</pre></div>
214
215	<P>
216	which would result in
217
218	<P>
219	<div class="verbatim"><pre>
220	Wed, 21 Jul 2004 15:35:16 ERROR Pack my box with 5 dozen liquor jugs
221	</pre></div>
222
223	<P>
224
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