unicode table information about a character in python

浪子不回头ぞ 提交于 2019-11-29 12:13:45

The standard module unicodedata defines a lot of properties, but not everything. A quick peek at its source confirms this.

Fortunately unicodedata.txt, the data file where this comes from, is not hard to parse. Each line consists of exactly 15 elements, ; separated, which makes it ideal for parsing. Using the description of the elements on ftp://ftp.unicode.org/Public/3.0-Update/UnicodeData-3.0.0.html, you can create a few classes to encapsulate the data. I've taken the names of the class elements from that list; the meaning of each of the elements is explained on that same page.

Make sure to download ftp://ftp.unicode.org/Public/UNIDATA/UnicodeData.txt and ftp://ftp.unicode.org/Public/UNIDATA/Blocks.txt first, and put them inside the same folder as this program.

Code (tested with Python 2.7 and 3.6):

# -*- coding: utf-8 -*-

class UnicodeCharacter:
    def __init__(self):
        self.code = 0
        self.name = 'unnamed'
        self.category = ''
        self.combining = ''
        self.bidirectional = ''
        self.decomposition = ''
        self.asDecimal = None
        self.asDigit = None
        self.asNumeric = None
        self.mirrored = False
        self.uc1Name = None
        self.comment = ''
        self.uppercase = None
        self.lowercase = None
        self.titlecase = None
        self.block = None

    def __getitem__(self, item):
        return getattr(self, item)

    def __repr__(self):
        return '{'+self.name+'}'

class UnicodeBlock:
    def __init__(self):
        self.first = 0
        self.last = 0
        self.name = 'unnamed'

    def __repr__(self):
        return '{'+self.name+'}'

class BlockList:
    def __init__(self):
        self.blocklist = []
        with open('Blocks.txt','r') as uc_f:
            for line in uc_f:
                line = line.strip(' \r\n')
                if '#' in line:
                    line = line.split('#')[0].strip()
                if line != '':
                    rawdata = line.split(';')
                    block = UnicodeBlock()
                    block.name = rawdata[1].strip()
                    rawdata = rawdata[0].split('..')
                    block.first = int(rawdata[0],16)
                    block.last = int(rawdata[1],16)
                    self.blocklist.append(block)
            # make 100% sure it's sorted, for quicker look-up later
            # (it is usually sorted in the file, but better make sure)
            self.blocklist.sort (key=lambda x: block.first)

    def lookup(self,code):
        for item in self.blocklist:
            if code >= item.first and code <= item.last:
                return item.name
        return None

class UnicodeList:
    """UnicodeList loads Unicode data from the external files
    'UnicodeData.txt' and 'Blocks.txt', both available at unicode.org

    These files must appear in the same directory as this program.

    UnicodeList is a new interpretation of the standard library
    'unicodedata'; you may first want to check if its functionality
    suffices.

    As UnicodeList loads its data from an external file, it does not depend
    on the local build from Python (in which the Unicode data gets frozen
    to the then 'current' version).

    Initialize with

        uclist = UnicodeList()
    """
    def __init__(self):

        # we need this first
        blocklist = BlockList()
        bpos = 0

        self.codelist = []
        with open('UnicodeData.txt','r') as uc_f:
            for line in uc_f:
                line = line.strip(' \r\n')
                if '#' in line:
                    line = line.split('#')[0].strip()
                if line != '':
                    rawdata = line.strip().split(';')
                    parsed = UnicodeCharacter()
                    parsed.code = int(rawdata[0],16)
                    parsed.characterName = rawdata[1]
                    parsed.category = rawdata[2]
                    parsed.combining = rawdata[3]
                    parsed.bidirectional = rawdata[4]
                    parsed.decomposition = rawdata[5]
                    parsed.asDecimal = int(rawdata[6]) if rawdata[6] else None
                    parsed.asDigit = int(rawdata[7]) if rawdata[7] else None
                    # the following value may contain a slash:
                    #  ONE QUARTER ... 1/4
                    # let's make it Python 2.7 compatible :)
                    if '/' in rawdata[8]:
                        rawdata[8] = rawdata[8].replace('/','./')
                        parsed.asNumeric = eval(rawdata[8])
                    else:
                        parsed.asNumeric = int(rawdata[8]) if rawdata[8] else None
                    parsed.mirrored = rawdata[9] == 'Y'
                    parsed.uc1Name = rawdata[10]
                    parsed.comment = rawdata[11]
                    parsed.uppercase = int(rawdata[12],16) if rawdata[12] else None
                    parsed.lowercase = int(rawdata[13],16) if rawdata[13] else None
                    parsed.titlecase = int(rawdata[14],16) if rawdata[14] else None
                    while bpos < len(blocklist.blocklist) and parsed.code > blocklist.blocklist[bpos].last:
                        bpos += 1
                    parsed.block = blocklist.blocklist[bpos].name if bpos < len(blocklist.blocklist) and parsed.code >= blocklist.blocklist[bpos].first else None
                    self.codelist.append(parsed)

    def find_code(self,codepoint):
        """Find the Unicode information for a codepoint (as int).

        Returns:
            a UnicodeCharacter class object or None.
        """
        # the list is unlikely to contain duplicates but I have seen Unicode.org
        # doing that in similar situations. Again, better make sure.
        val = [x for x in self.codelist if codepoint == x.code]
        return val[0] if val else None

    def find_char(self,str):
        """Find the Unicode information for a codepoint (as character).

        Returns:
            for a single character: a UnicodeCharacter class object or
            None.
            for a multicharacter string: a list of the above, one element
            per character.
        """
        if len(str) > 1:
            result = [self.find_code(ord(x)) for x in str]
            return result
        else:
            return self.find_code(ord(str))

When loaded, you can now look up a character code with

>>> ul = UnicodeList()     # ONLY NEEDED ONCE!
>>> print (ul.find_code(0x204))
{LATIN CAPITAL LETTER E WITH DOUBLE GRAVE}

which by default is shown as the name of a character (Unicode calls this a 'code point'), but you can retrieve other properties as well:

>>> print ('%04X' % uc.find_code(0x204).lowercase)
0205
>>> print (ul.lookup(0x204).block)
Latin Extended-B

and (as long as you don't get a None) even chain them:

>>> print (ul.find_code(ul.find_code(0x204).lowercase))
{LATIN SMALL LETTER E WITH DOUBLE GRAVE}

It does not rely on your particular build of Python; you can always download an updated list from unicode.org and be assured to get the most recent information:

import unicodedata
>>> print (unicodedata.name('\U0001F903'))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: no such name
>>> print (uclist.find_code(0x1f903))
{LEFT HALF CIRCLE WITH FOUR DOTS}

(As tested with Python 3.5.3.)

There are currently two lookup functions defined:

  • find_code(int) looks up character information by codepoint as an integer.
  • find_char(string) looks up character information for the character(s) in string. If there is only one character, it returns a UnicodeCharacter object; if there are more, it returns a list of objects.

After import unicodelist (assuming you saved this as unicodelist.py), you can use

>>> ul = UnicodeList()
>>> hex(ul.find_char(u'è').code)
'0xe8'

to look up the hex code for any character, and a list comprehension such as

>>> l = [hex(ul.find_char(x).code) for x in 'Hello']
>>> l
['0x48', '0x65', '0x6c', '0x6c', '0x6f']

for longer strings. Note that you don't actually need all of this if all you want is a hex representation of a string! This suffices:

 l = [hex(ord(x)) for x in 'Hello']

The purpose of this module is to give easy access to other Unicode properties. A longer example:

str = 'Héllo...'
dest = ''
for i in str:
    dest += chr(ul.find_char(i).uppercase) if ul.find_char(i).uppercase is not None else i
print (dest)

HÉLLO...

and showing a list of properties for a character per your example:

letter = u'Ȅ'
print ('Name > '+ul.find_char(letter).name)
print ('Unicode number > U+%04x' % ul.find_char(letter).code)
print ('Bloc > '+ul.find_char(letter).block)
print ('Lowercase > %s' % chr(ul.find_char(letter).lowercase))

(I left out HTML; these names are not defined in the Unicode standard.)

The unicodedata documentation shows how to do most of this.

The Unicode block name is apparently not available but another Stack Overflow question has a solution of sorts and another has some additional approaches using regex.

The uppercase/lowercase mapping and character number information is not particularly Unicode-specific; just use the regular Python string functions.

So in summary

>>> import unicodedata
>>> unicodedata.name('Ë')
'LATIN CAPITAL LETTER E WITH DIAERESIS'
>>> 'U+%04X' % ord('Ë')
'U+00CB'
>>> '&#%i;' % ord('Ë')
'&#203;'
>>> 'Ë'.lower()
'ë'

The U+%04X formatting is sort-of correct, in that it simply avoids padding and prints the whole hex number for code points with a value higher than 65,535. Note that some other formats require the use of %08X padding in this scenario (notably \U00010000 format in Python).

You can do this in some ways :

1- create an API yourself ( I can't find anything that do this )
2- create table in database or excel file
3- load and parse a website to do that

I think the 3rd way is very easy. take a look as This Page. you can find some information there Unicodes.

Get your Unicode number and then, find it in web page using parse tools like LXML , Scrapy , Selenium , etc

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