Fix logging usage across docs

docs/topics/debug.rst

@@ -132,16 +132,13 @@ Logging is another useful option for getting information about your spider run.
 Although not as convenient, it comes with the advantage that the logs will be
 available in all future runs should they be necessary again::
 
-    from scrapy import log
-
     def parse_details(self, response):
         item = response.meta.get('item', None)
         if item:
             # populate more `item` fields
             return item
         else:
-            self.log('No item received for %s' % response.url,
-                level=log.WARNING)
+            self.logger.warning('No item received for %s', response.url)
 
 For more information, check the :ref:`topics-logging` section.
 

docs/topics/extensions.rst

@@ -102,9 +102,12 @@ number of items will be specified through the ``MYEXT_ITEMCOUNT`` setting.
 
 Here is the code of such extension::
 
+    import logging
     from scrapy import signals
     from scrapy.exceptions import NotConfigured
 
+    logger = logging.getLogger(__name__)
+
     class SpiderOpenCloseLogging(object):
 
         def __init__(self, item_count):
@@ -133,15 +136,15 @@ Here is the code of such extension::
             return ext
 
         def spider_opened(self, spider):
-            spider.log("opened spider %s" % spider.name)
+            logger.info("opened spider %s", spider.name)
 
         def spider_closed(self, spider):
-            spider.log("closed spider %s" % spider.name)
+            logger.info("closed spider %s", spider.name)
 
         def item_scraped(self, item, spider):
             self.items_scraped += 1
             if self.items_scraped % self.item_count == 0:
-                spider.log("scraped %d items" % self.items_scraped)
+                logger.info("scraped %d items", self.items_scraped)
                 
 
 .. _topics-extensions-ref:

docs/topics/practices.rst

@@ -30,9 +30,12 @@ project as example.
 
     from twisted.internet import reactor
     from scrapy.crawler import CrawlerRunner
+    from scrapy.utils.log import configure_logging
     from scrapy.utils.project import get_project_settings
 
-    runner = CrawlerRunner(get_project_settings())
+    settings = get_project_settings()
+    configure_logging(settings)
+    runner = CrawlerRunner(settings)
 
     # 'followall' is the name of one of the spiders of the project.
     d = runner.crawl('followall', domain='scrapinghub.com')
@@ -54,11 +57,13 @@ the spider class as first argument in the :meth:`CrawlerRunner.crawl
     from twisted.internet import reactor
     import scrapy
     from scrapy.crawler import CrawlerRunner
+    from scrapy.utils.log import configure_logging
 
     class MySpider(scrapy.Spider):
         # Your spider definition
         ...
 
+    configure_logging(settings)
     runner = CrawlerRunner({
         'USER_AGENT': 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)'
     })
@@ -85,9 +90,12 @@ Here is an example that runs multiple spiders simultaneously, using the
 
     from twisted.internet import reactor, defer
     from scrapy.crawler import CrawlerRunner
+    from scrapy.utils.log import configure_logging
     from scrapy.utils.project import get_project_settings
 
-    runner = CrawlerRunner(get_project_settings())
+    settings = get_project_settings()
+    configure_logging(settings)
+    runner = CrawlerRunner(settings)
     dfs = set()
     for domain in ['scrapinghub.com', 'insophia.com']:
         d = runner.crawl('followall', domain=domain)
@@ -102,9 +110,12 @@ Same example but running the spiders sequentially by chaining the deferreds:
 
     from twisted.internet import reactor, defer
     from scrapy.crawler import CrawlerRunner
+    from scrapy.utils.log import configure_logging
     from scrapy.utils.project import get_project_settings
 
-    runner = CrawlerRunner(get_project_settings())
+    settings = get_project_settings()
+    configure_logging(settings)
+    runner = CrawlerRunner(settings)
 
     @defer.inlineCallbacks
     def crawl():

docs/topics/request-response.rst

@@ -189,7 +189,7 @@ Example::
 
     def parse_page2(self, response):
         # this would log http://www.example.com/some_page.html
-        self.log("Visited %s" % response.url)
+        self.logger.info("Visited %s", response.url)
 
 In some cases you may be interested in passing arguments to those callback
 functions so you can receive the arguments later, in the second callback. You
@@ -382,7 +382,7 @@ method for this job. Here's an example spider which uses it::
         def after_login(self, response):
             # check login succeed before going on
             if "authentication failed" in response.body:
-                self.log("Login failed", level=log.ERROR)
+                self.logger.error("Login failed")
                 return
 
             # continue scraping with authenticated session...

docs/topics/spiders.rst

@@ -224,7 +224,7 @@ Let's see an example::
         ]
 
         def parse(self, response):
-            self.log('A response from %s just arrived!' % response.url)
+            self.logger.info('A response from %s just arrived!', response.url)
 
 Return multiple Requests and items from a single callback::
 
@@ -412,7 +412,7 @@ Let's now take a look at an example CrawlSpider with rules::
         )
 
         def parse_item(self, response):
-            self.log('Hi, this is an item page! %s' % response.url)
+            self.logger.info('Hi, this is an item page! %s', response.url)
             item = scrapy.Item()
             item['id'] = response.xpath('//td[@id="item_id"]/text()').re(r'ID: (\d+)')
             item['name'] = response.xpath('//td[@id="item_name"]/text()').extract()
@@ -515,7 +515,6 @@ XMLFeedSpider example
 
 These spiders are pretty easy to use, let's have a look at one example::
 
-    from scrapy import log
     from scrapy.contrib.spiders import XMLFeedSpider
     from myproject.items import TestItem
 
@@ -527,7 +526,7 @@ These spiders are pretty easy to use, let's have a look at one example::
         itertag = 'item'
 
         def parse_node(self, response, node):
-            log.msg('Hi, this is a <%s> node!: %s' % (self.itertag, ''.join(node.extract())))
+            self.logger.info('Hi, this is a <%s> node!: %s', self.itertag, ''.join(node.extract()))
 
             item = TestItem()
             item['id'] = node.xpath('@id').extract()
@@ -576,7 +575,6 @@ CSVFeedSpider example
 Let's see an example similar to the previous one, but using a
 :class:`CSVFeedSpider`::
 
-    from scrapy import log
     from scrapy.contrib.spiders import CSVFeedSpider
     from myproject.items import TestItem
 
@@ -589,7 +587,7 @@ Let's see an example similar to the previous one, but using a
         headers = ['id', 'name', 'description']
 
         def parse_row(self, response, row):
-            log.msg('Hi, this is a row!: %r' % row)
+            self.logger.info('Hi, this is a row!: %r', row)
 
             item = TestItem()
             item['id'] = row['id']