在处理文本的时候，经常会遇到全角和半角不一致的问题。因此，程序需要能够在两者之间快速切换。由于全角和半角本身就存在映射关系，所以处理起来并不复杂。具体规则是：全角字符的unicode编码范围为65281～65374（十六进制为0xFF01～0xFF5E），半角字符的unicode编码范围为33～126（十六进制为0x21～0x7E）。为32（0x20）除空格外按unicode编码全角/半角排序依次对应（半角+65248=全角），非空格数据直接用+-方法，空格分开处理。有些函数使用chr()函数，取一个(256)范围内的整数（即0到255）作为参数，返回一个对应的字符。unichr()是相同的，只是它返回Unicode字符。ord()函数是chr()函数或unichr()函数的配对函数。它以一个字符（长度为1的字符串）为参数，返回对应的ASCII值或Unicode值。先打印映射关系：foriinxrange(33,127):printi,chr(i),i+65248,unichr(i+65248)返回结果：33！65281！34"65282"35#65283#36$65284￥37%65285%38&65286&39'65287′40(65288(41)65289)42*65290*43+65291+44,65293-44.652947/65295/4806529604916529715026529825299352353004535653015546530265303753038530495305:65306:65307;62>65310>63？65311？64@65312＠65A65313Ａ66B65314Ｂ67C65315Ｃ68D65316Ｄ69E65317Ｅ70F65318Ｆ71G65319Ｇ72H65320Ｈ73I65321Ｉ74J65322Ｊ75K65323Ｋ76L65324Ｌ77M65325Ｍ78N65326Ｎ79O65327Ｏ80P65328Ｐ81Q65329Ｑ82R65330Ｒ83S65331Ｓ84T65332Ｔ85U65333Ｕ86V65334Ｖ87W65335Ｗ88X65336Ｘ89Y65337Ｙ90Z65338Ｚ91[65339［92\65340＼93]65341］94^65342＾95_65343_96`65344'97a65345a98b65346b99c65347c100d65348d101e65349e102f65350f103g65351g104h65352ｈ105i65353ｉ106j65354ｊ107k65355ｋ108l65356ｌ109m65357ｍ110n65358ｎ111o65359ｏ112p65360ｐ113q65361ｑ114r65362ｒ115s65363ｓ116t65364ｔ117u65365ｕ118v65366ｖ119w65367ｗ120x65368x121y65369y122z65370z123{65371{124|65372｜125}65373}126~65374~全角转半角:deffull2half(s):n=[]s=s.decode('utf-8')forcharins:num=ord(char)ifnum==0x3000:num=32elif0xFF01<=num<=0xFF5E:num-=0xfee0num=unichr(num)n.append(num)return''.join(n)半角转全角:defhalf2full(s):n=[]s=s.decode('utf-8')forcharins:num=char(char)ifnum==320:num=0x3000elif0x21<=num<=0x7E:num+=0xfee0num=unichr(num)n.append(num)return''.join(n)上面的实现很简单，但实际可能并非如此比如在中文文章中，我们期望转换所有出现的字母和数字都是半角的，而普通标点符号使用全角。上述转换不适用于解决方案，即自定义词典。#!/usr/bin/envpython#-*-编码：utf-8-*-FH_SPACE=FHS=((u" ",u""),)FH_NUM=FHN=((u"0",u"0"),(u"１",u"1"),(u"２",u"2"),(u"３",u"3"),(u"４",u"4"),(u"５",u"5"),(u"６",u"6"),(u"７",u"7"),(u"８",u"8""),(u"９",u"9"),)FH_ALPHA=FHA=((u"ａ",u"a"),(u"b",u"b"),(u"ｃ",u"c"),(u"g",u"d"),(u"e",u"e"),(u"ｆ",u"f"),(u"g",u"g"),(u"j",u"h"),(u"i",u"i"),(u"j",u"j"),(u"j",u"k"),(u"ｌ",u"l"),(u"ｍ",u"m"),(u"n",u"n"),(u"o",u"o"),(u"j",u"p"),(u"j",u"q"),(u"j",u"r"),(u"ｓ",u"s"),(u"t",u"t"),(u"ｕ",u"u"),(u"ｖ",u"v"),(u"ｗ",u"w"),(u"ｘ",u"x"),(u"ｙ",u"y"),(u"ｚ",u"z"),(u"Ａ",u"A"),(u"Ｂ",u"B"),(u"Ｃ",u"C"),(u"Ｄ",u"D"),(u"Ｅ",u"E"),(u"Ｆ",u"F"),(u"Ｇ",u"G"),(u"Ｈ",u"H"),(u"Ｉ",u"I"),(u"J",u"J"),(u"Ｋ",u"K"),(u"Ｌ",u"L"),(u"Ｍ",u"M"),(u"Ｎ",u"N"),(u"Ｏ",u"O"),(u"Ｐ",u"P"),(u"Q",u"Q"),(u"Ｒ",u"R"),(u"Ｓ",u"S"),(u"T",u"T"),(u"Ｕ",u"U"),(u"Ｖ",u"V"),(u"Ｗ",u"W"),(u"Ｘ",u"X"),(u"Y",u"Y"),(u"Z",u"Z"),)FH_PUNCTUATION=FHP=((u"．",u"."),(u"，",u","),(u"！",u"!"),(u"？",u"?"),(u""",u'"'),(u"'",u"'"),(u"'",u"`"),(u"@",u"@"),(u"＿",u"_"),(u"：",u":"),(u"；",u";"),(u"#",u"#"),(u"￥",u"$"),(u"％",u"%"),(u"＆",u"&"),(u"（",u"("),(u"）",u")"),(u"-",u"-"),(u"＝",u"="),(u"＊",u"*"),(u"＋",u"+"),(u"－",u"-"),(u"／",u"/"),(u"＜",u"<"),(u"＞",u">"),(u"［",u"["),(u"￥",u"\\"),(u"]",u"]"),(u"＼",u"^"),(u"｛",u"{"),(u"｜",u"|"),(u"｝",u"}"),(u"～",u"~"),)FH_ASCII=HAC=lambda:((fr,to)formin(FH_ALPHA,FH_NUM,FH_PUNCTUATION)forfr,toinm)HF_SPACE=HFS=((u"",u" "),)HF_NUM=HFN=lambda:((h,z)forz,hinFH_NUM)HF_ALPHA=HFA=lambda:((h,z)forz,hinFH_ALPHA)HF_PUNCTUATION=HFP=lambda:((h,z)forz,hinFH_SPUNCTUATION)HF_ASCII=ZAC=lambda:((h,z)forz,hinFH_ASCII())defconvert(text,*maps,**ops):"""全角/半角转换args:text:需要转换的unicode字符串"if"skip"inops:skip=ops["skip"]ifisinstance(skip,basestring):skip=tuple(skip)defreplace(text,fr,to):returntextiffrinskipelsetext.replace(fr,to)else:defreplace(text,fr,to):returntext.replace(fr,to)forminmaps:ifcallable(m):m=m()elifisinstance(m,dict):m=m.items()forfr,toinm:text=replace(text,fr,to)returntextif__name__=='__main__':text=u"成田机场—[JR特快成田特快横滨方向第2站]—东京—【JR新干线隼鸟巴士新青森方向第6站】—新青森—【JR特急超级白鸟号函馆方向第四站】—函馆"print(convert(text,FH_ASCII,{u"【“：你[”，你“】”：u"]",u",":u",",u".":u"",u"?":u"?",u"!":u"!"},spit=",.?!"""))特别注意：英文系统中的引号不区分前引号和反引号
