root/tools.py

# Copyright (C) 2007, Stefan Schwarzer
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import md5
import os
import re


def normalize_path(path):
    """
    Return the file system path `path` in "normalized" form:
    - change each sequence of path separators to a single path separator
    - change path by evaluating "." and ".." occurences
    - make path absolute
    """
    # funny workaround for backslash separator :-/
    if os.sep == "\\":
        replacement = "\\\\"
    else:
        replacement = os.sep
    path = re.sub("(?:%s)+" % re.escape(os.sep), replacement, path)
    path = os.path.normcase(os.path.normpath(path))
    return os.path.abspath(path)

def url_to_anchor(url):
    """
    Return a string, specific for the URL `url`, which is usable as an
    anchor in HTML links.
    """
    # this implementation has a _very_ small chance to reuse the same
    #  anchor for different URLs
    return md5.new(url).hexdigest()[:10]