old_contents: # Copyright 2014 Donald Stufft
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  from __future__ import absolute_import, division, print_function
  
  import bleach
  
  
  ALLOWED_TAGS = [
      # Bleach Defaults
      "a", "abbr", "acronym", "b", "blockquote", "code", "em", "i", "li", "ol",
      "strong", "ul",
  
      # Custom Additions
      "br", "cite", "col", "colgroup", "dd", "div", "dl", "dt", "h1", "h2", "h3",
      "h4", "h5", "h6", "hr", "img", "p", "pre", "span", "table", "tbody", "td",
      "th", "thead", "tr", "tt",
  ]
  
  ALLOWED_ATTRIBUTES = {
      # Bleach Defaults
      "a": ["href", "title"],
      "abbr": ["title"],
      "acronym": ["title"],
  
      # Custom Additions
      "*": ["id"],
      "hr": ["class"],
      "img": ["src"],
      "span": ["class"],
  }
  
  ALLOWED_STYLES = []
  
  
  def clean(html):
      def nofollow(attrs, new=False):
          if attrs["href"].startswith("mailto:"):
              return attrs
          attrs["rel"] = "nofollow"
          return attrs
  
      # Clean the output using Bleach
      cleaned = bleach.clean(
          html,
          tags=ALLOWED_TAGS,
          attributes=ALLOWED_ATTRIBUTES,
          styles=ALLOWED_STYLES,
      )
  
      # Bleach Linkify makes it easy to modify links, however, we will not be
      # using it to create additional links.
      cleaned = bleach.linkify(
          cleaned,
          callbacks=[
              lambda attrs, new: attrs if not new else None,
              nofollow,
          ],
          skip_pre=True,
          parse_email=False,
      )
  
      return cleaned
  
new_contents: # Copyright 2014 Donald Stufft
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  from __future__ import absolute_import, division, print_function
  
  import bleach
  
  
  ALLOWED_TAGS = [
      # Bleach Defaults
      "a", "abbr", "acronym", "b", "blockquote", "code", "em", "i", "li", "ol",
      "strong", "ul",
  
      # Custom Additions
      "br", "cite", "col", "colgroup", "dd", "div", "dl", "dt", "h1", "h2", "h3",
      "h4", "h5", "h6", "hr", "img", "p", "pre", "span", "table", "tbody", "td",
      "th", "thead", "tr", "tt", "kbd", "var",
  ]
  
  ALLOWED_ATTRIBUTES = {
      # Bleach Defaults
      "a": ["href", "title"],
      "abbr": ["title"],
      "acronym": ["title"],
  
      # Custom Additions
      "*": ["id"],
      "hr": ["class"],
      "img": ["src"],
      "span": ["class"],
  }
  
  ALLOWED_STYLES = []
  
  
  def clean(html):
      def nofollow(attrs, new=False):
          if attrs["href"].startswith("mailto:"):
              return attrs
          attrs["rel"] = "nofollow"
          return attrs
  
      # Clean the output using Bleach
      cleaned = bleach.clean(
          html,
          tags=ALLOWED_TAGS,
          attributes=ALLOWED_ATTRIBUTES,
          styles=ALLOWED_STYLES,
      )
  
      # Bleach Linkify makes it easy to modify links, however, we will not be
      # using it to create additional links.
      cleaned = bleach.linkify(
          cleaned,
          callbacks=[
              lambda attrs, new: attrs if not new else None,
              nofollow,
          ],
          skip_pre=True,
          parse_email=False,
      )
  
      return cleaned
  
subject: Whitelist <kbd> and <var>