SP/web2py/gluon/contrib/pyuca/pyuca.py
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2018-10-25 23:33:13 +08:00

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Python

# pyuca - Unicode Collation Algorithm
# Version: 2012-06-21
#
# James Tauber
# http://jtauber.com/
# Copyright (c) 2006-2012 James Tauber and contributors
#
# 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.
"""
Preliminary implementation of the Unicode Collation Algorithm.
This only implements the simple parts of the algorithm but I have successfully
tested it using the Default Unicode Collation Element Table (DUCET) to collate
Ancient Greek correctly.
Usage example:
from pyuca import Collator
c = Collator("allkeys.txt")
sorted_words = sorted(words, key=c.sort_key)
allkeys.txt (1 MB) is available at
http://www.unicode.org/Public/UCA/latest/allkeys.txt
but you can always subset this for just the characters you are dealing with.
"""
class Node:
def __init__(self):
self.value = None
self.children = {}
class Trie:
def __init__(self):
self.root = Node()
def add(self, key, value):
curr_node = self.root
for part in key:
curr_node = curr_node.children.setdefault(part, Node())
curr_node.value = value
def find_prefix(self, key):
curr_node = self.root
remainder = key
for part in key:
if part not in curr_node.children:
break
curr_node = curr_node.children[part]
remainder = remainder[1:]
return (curr_node.value, remainder)
class Collator:
def __init__(self, filename):
self.table = Trie()
self.load(filename)
def load(self, filename):
for line in open(filename):
if line.startswith("#") or line.startswith("%"):
continue
if line.strip() == "":
continue
line = line[:line.find("#")] + "\n"
line = line[:line.find("%")] + "\n"
line = line.strip()
if line.startswith("@"):
pass
else:
semicolon = line.find(";")
charList = line[:semicolon].strip().split()
x = line[semicolon:]
collElements = []
while True:
begin = x.find("[")
if begin == -1:
break
end = x[begin:].find("]")
collElement = x[begin:begin+end+1]
x = x[begin + 1:]
alt = collElement[1]
chars = collElement[2:-1].split(".")
collElements.append((alt, chars))
integer_points = [int(ch, 16) for ch in charList]
self.table.add(integer_points, collElements)
def sort_key(self, string):
collation_elements = []
lookup_key = [ord(ch) for ch in string]
while lookup_key:
value, lookup_key = self.table.find_prefix(lookup_key)
if not value:
# Calculate implicit weighting for CJK Ideographs
# contributed by David Schneider 2009-07-27
# http://www.unicode.org/reports/tr10/#Implicit_Weights
value = []
value.append((".", ["%X" % (0xFB40 + (lookup_key[0] >> 15)), "0020", "0002", "0001"]))
value.append((".", ["%X" % ((lookup_key[0] & 0x7FFF) | 0x8000), "0000", "0000", "0000"]))
lookup_key = lookup_key[1:]
collation_elements.extend(value)
sort_key = []
for level in range(4):
if level:
sort_key.append(0) # level separator
for element in collation_elements:
ce_l = int(element[1][level], 16)
if ce_l:
sort_key.append(ce_l)
return tuple(sort_key)