I needed to strip the Chinese out of a bunch of strings today and was looking for a simple Python regex. Any suggestions?
The short, but relatively comprehensive answer for narrow Unicode builds of python (excluding ordinals > 65535 which can only be represented in narrow Unicode builds via surrogate pairs):
RE = re.compile(u'[⺀-⺙⺛-⻳⼀-⿕々〇〡-〩〸-〺〻㐀-䶵一-鿃豈-鶴侮-頻並-龎]', re.UNICODE)
nochinese = RE.sub('', mystring)
The code for building the RE, and if you need to detect Chinese characters in the supplementary plane for wide builds:
# -*- coding: utf-8 -*-
import re
LHan = [[0x2E80, 0x2E99], # Han # So [26] CJK RADICAL REPEAT, CJK RADICAL RAP
[0x2E9B, 0x2EF3], # Han # So [89] CJK RADICAL CHOKE, CJK RADICAL C-SIMPLIFIED TURTLE
[0x2F00, 0x2FD5], # Han # So [214] KANGXI RADICAL ONE, KANGXI RADICAL FLUTE
0x3005, # Han # Lm IDEOGRAPHIC ITERATION MARK
0x3007, # Han # Nl IDEOGRAPHIC NUMBER ZERO
[0x3021, 0x3029], # Han # Nl [9] HANGZHOU NUMERAL ONE, HANGZHOU NUMERAL NINE
[0x3038, 0x303A], # Han # Nl [3] HANGZHOU NUMERAL TEN, HANGZHOU NUMERAL THIRTY
0x303B, # Han # Lm VERTICAL IDEOGRAPHIC ITERATION MARK
[0x3400, 0x4DB5], # Han # Lo [6582] CJK UNIFIED IDEOGRAPH-3400, CJK UNIFIED IDEOGRAPH-4DB5
[0x4E00, 0x9FC3], # Han # Lo [20932] CJK UNIFIED IDEOGRAPH-4E00, CJK UNIFIED IDEOGRAPH-9FC3
[0xF900, 0xFA2D], # Han # Lo [302] CJK COMPATIBILITY IDEOGRAPH-F900, CJK COMPATIBILITY IDEOGRAPH-FA2D
[0xFA30, 0xFA6A], # Han # Lo [59] CJK COMPATIBILITY IDEOGRAPH-FA30, CJK COMPATIBILITY IDEOGRAPH-FA6A
[0xFA70, 0xFAD9], # Han # Lo [106] CJK COMPATIBILITY IDEOGRAPH-FA70, CJK COMPATIBILITY IDEOGRAPH-FAD9
[0x20000, 0x2A6D6], # Han # Lo [42711] CJK UNIFIED IDEOGRAPH-20000, CJK UNIFIED IDEOGRAPH-2A6D6
[0x2F800, 0x2FA1D]] # Han # Lo [542] CJK COMPATIBILITY IDEOGRAPH-2F800, CJK COMPATIBILITY IDEOGRAPH-2FA1D
def build_re():
L = []
for i in LHan:
if isinstance(i, list):
f, t = i
try:
f = unichr(f)
t = unichr(t)
L.append('%s-%s' % (f, t))
except:
pass # A narrow python build, so can't use chars > 65535 without surrogate pairs!
else:
try:
L.append(unichr(i))
except:
pass
RE = '[%s]' % ''.join(L)
print 'RE:', RE.encode('utf-8')
return re.compile(RE, re.UNICODE)
RE = build_re()
print RE.sub('', u'美国').encode('utf-8')
print RE.sub('', u'blah').encode('utf-8')
Python 2:
#!/usr/bin/env python
# -*- encoding: utf8 -*-
import re
sample = u'I am from 美国。We should be friends. 朋友。'
for n in re.findall(ur'[\u4e00-\u9fff]+',sample):
print n
Python 3:
sample = 'I am from 美国。We should be friends. 朋友。'
for n in re.findall(r'[\u4e00-\u9fff]+', sample):
print(n)
Output:
美国
朋友
About Unicode code blocks:
The 4E00—9FFF
range covers CJK Unified Ideographs (CJK=Chinese, Japanese and Korean). There are a number of lower ranges that relate, to some degree, to CJK:
31C0—31EF CJK Strokes
31F0—31FF Katakana Phonetic Extensions
3200—32FF Enclosed CJK Letters and Months
3300—33FF CJK Compatibility
3400—4DBF CJK Unified Ideographs Extension A
4DC0—4DFF Yijing Hexagram Symbols
4E00—9FFF CJK Unified Ideographs