Added tag cloud generation. Result stored in the context.tag_cloud as list of tuples (tag, weight). Weight is from 1 to TAG_CLOUD_STEPS, lesser weight corresponds to bigger font size.

docs/settings.rst

@@ -60,6 +60,8 @@ Setting name              what it does ?
 `STATIC_THEME_PATHS`      Static theme paths you want to copy. Default values
                           is `static`, but if your theme have others static paths,
                           you can put them here.
+`TAG_CLOUD_STEPS`         Count of different font sizes in the tag cloud.
+`TAG_CLOUD_MAX_ITEMS`     Maximum tags count in the cloud.
 `THEME`                   theme to use to product the output. can be the
                           complete static path to a theme folder, or chosen
                           between the list of default themes (see below)

pelican/generators.py

@@ -1,9 +1,11 @@
-from operator import attrgetter
+from operator import attrgetter, itemgetter
 from itertools import chain
 from functools import partial
 from datetime import datetime
 from collections import defaultdict
 import os
+import math
+import random
 
 from jinja2 import Environment, FileSystemLoader
 from jinja2.exceptions import TemplateNotFound
@@ -193,8 +195,34 @@ class ArticlesGenerator(Generator):
         self.dates = list(self.articles)
         self.dates.sort(key=attrgetter('date'), 
                 reverse=self.context['REVERSE_ARCHIVE_ORDER'])
+
+        # create tag cloud
+        tag_cloud = defaultdict(int)
+        for article in self.articles:
+            for tag in article.tags:
+                tag_cloud[tag] += 1
+
+        tag_cloud = sorted(tag_cloud.items(), key = itemgetter(1), reverse = True)
+        tag_cloud = tag_cloud[:self.settings.get('TAG_CLOUD_MAX_ITEMS')]
+
+        max_count = max(map(itemgetter(1), tag_cloud))
+        steps = self.settings.get('TAG_CLOUD_STEPS')
+
+        # calculate word sizes
+        self.tag_cloud = [
+            (
+                tag,
+                int(
+                    math.floor(steps - (steps - 1) * math.log(count) / math.log(max_count))
+                )
+            )
+            for tag, count in tag_cloud
+        ]
+        # put words in chaos
+        random.shuffle(self.tag_cloud)
+
         # and generate the output :)
-        self._update_context(('articles', 'dates', 'tags', 'categories'))
+        self._update_context(('articles', 'dates', 'tags', 'categories', 'tag_cloud'))
 
     def generate_output(self, writer):
         self.generate_feeds(writer)

pelican/settings.py

@@ -22,6 +22,8 @@ _DEFAULT_CONFIG = {'PATH': None,
                    'CLEAN_URLS': False, # use /blah/ instead /blah.html in urls
                    'RELATIVE_URLS': True,
                    'DEFAULT_LANG': 'en',
+                   'TAG_CLOUD_STEPS': 4,
+                   'TAG_CLOUD_MAX_ITEMS': 100,
                   }
 
 def read_settings(filename):