{"id":55,"date":"2016-03-23T22:14:16","date_gmt":"2016-03-23T14:14:16","guid":{"rendered":"http:\/\/www.5x44.cn\/?p=55"},"modified":"2016-04-07T21:35:24","modified_gmt":"2016-04-07T13:35:24","slug":"%e7%ac%ac4%e7%ab%a0-string","status":"publish","type":"post","link":"https:\/\/www.5x44.cn\/?p=55","title":{"rendered":"\u7b2c4\u7ae0 String"},"content":{"rendered":"

\uff081\uff09\u6bcf\u4e2aUNICODE\u5b57\u7b264\u5b57\u8282\u5927\u5c0f\uff0c\u53ef\u4ee5\u7528UNICODE\u63cf\u8ff0\u6bcf\u79cd\u8bed\u8a00\u7684\u6bcf\u4e00\u4e2a\u5b57\u7b26\uff0c\u65e0\u8bba\u5f53\u524d\u8bed\u8a00\u6709\u6ca1\u6709\u201cA\u201d\u8fd9\u4e2a\u5b57\u7b26\uff0cU+0041\u8fd9\u4e2aUNICODE\u4ee3\u7801\u90fd\u4ee3\u8868\u5b57\u7b26”A”\u3002<\/p>\n

\uff082\uff09UNICODE\u7f16\u7801\u88ab\u79f0\u505aUTF-32\uff0c\u56e0\u4e3a32\u4f4d\u7b49\u4e8e4\u5b57\u8282\u3002\u8fd9\u6709\u4e00\u4e2a\u4f18\u70b9\uff0c\u8981\u627e\u7b2cN\u4e2a\u5b57\u7b26\uff0c\u5b83\u6240\u5728\u7684\u4f4d\u7f6e\u5c31\u57284*N\u5b57\u8282\u5904\u3002\u7f3a\u70b9\u5c31\u662f\u6d6a\u8d39\u5f88\u591a\u7a7a\u95f4\u3002<\/p>\n

\uff083\uff09\u56e0\u4e3a\u591a\u6570\u7528\u6237\u6240\u4f7f\u7528\u7684\u5b57\u7b26\u4e0d\u4f1a\u8d85\u8fc765535.\u6240\u4ee5\u53e6\u4e00\u79cdUNICODE\u7f16\u7801\u88ab\u79f0\u505aUTF-16\uff0816bits = 2 bytes\uff09\u3002\u8d85\u8fc765535\u7684\u5b57\u7b26\u88ab\u6d88\u51cf\u4e86\u3002<\/p>\n

\uff084\uff09\u5728UTF-32\u548cUTF-16\u4e2d\u6709\u4e00\u4e2a\u4e0d\u660e\u663e\u7684\u7f3a\u70b9\u3002\u4e0d\u540c\u7684\u8ba1\u7b97\u673a\u7cfb\u7edf\u5b58\u50a8\u5355\u72ec\u7684\u5b57\u8282\u7684\u65b9\u5f0f\u4e0d\u540c\uff0c\u8fd9\u610f\u5473\u7740U+4E2D\u5728UTF-16\u4e2d\u53ef\u4ee5\u5b58\u50a8\u62104E 2D\u62162D 4E\uff0c\u8fd9\u4f9d\u8d56\u4e8e\u7cfb\u7edf\u662f\u9ad8\u4f4d\u5e8f\u8fd8\u662f\u4f4e\u4f4d\u5e8f\u3002\u5728\u540c\u4e00\u7cfb\u7edf\u4e0a\u4e0d\u4f1a\u6709\u4efb\u4f55\u95ee\u9898\uff0c\u4f46\u662f\u5982\u679c\u4f20\u8f93\u6587\u6863\u5230\u5176\u5b83\u7cfb\u7edf\u4e0a\uff0c\u90a3\u5c31\u5fc5\u987b\u901a\u8fc7\u67d0\u79cd\u65b9\u5f0f\u544a\u8bc9\u5bf9\u65b9\u4f7f\u7528\u54ea\u79cd\u201c\u4f4d\u5e8f\u201d\u3002\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u591a\u5b57\u8282unicode\u7f16\u7801\u5b9a\u4e49\u4e86\u201c\u5b57\u8282\u987a\u5e8f\u6807\u8bb0\u201d\uff0c\u5b83\u662f\u4e00\u4e2a\u7279\u6b8a\u7684\u4e0d\u53ef\u6253\u5370\u5b57\u7b26\uff0c\u5728\u6587\u6863\u7684\u5f00\u59cb\u6307\u660e\u6587\u6863\u7684\u5b57\u8282\u4f4d\u5e8f\u3002\u5bf9\u4e8eUTF-16\uff0c\u8fd9\u4e2a\u5b57\u7b26\u662fU+FEFF\uff1b\u6536\u5230\u7684\u65f6\u5019\u53ef\u80fd\u662fFF FE\uff0c\u4e5f\u53ef\u80fd\u662fFE FF\u3002<\/p>\n

\uff085\uff09UTF-16\u4e0d\u80fd\u4fdd\u8bc1\u6bcf\u4e2a\u5b57\u7b26\u90fd\u80fd\u7528\u4e24\u4e2a\u5b57\u8282\u8868\u793a\uff0c\u6240\u4ee5UTF-8\u8bde\u751f\u4e86\u3002UTF-8\u662fUNICODE\u7684\u53d8\u957f\u7f16\u7801\u7cfb\u7edf\uff0c\u4e0d\u540c\u7684\u5b57\u7b26\u4f7f\u7528\u4e0d\u540c\u6570\u91cf\u7684\u5b57\u8282\u3002\u5bf9\u4e8eASCII\u5b57\u7b26\uff08A-Z\uff09\u5728UTF-8\u4e2d\u6bcf\u4e2a\u5b57\u7b26\u53ea\u4f7f\u7528\u4e00\u4e2a\u5b57\u8282\u3002\u4e0d\u8fc7\u5b9e\u9645\u4e0a\u4f7f\u7528\u7684\u5b57\u8282\u6570\u8fd8\u662f\u4e00\u6837\u7684\uff0c\u56e0\u4e3a\u5728UTF-8\u4e2d\u524d128\u4e2a\u5b57\u7b26\uff080~127\uff09\u662f\u65e0\u6cd5\u5206\u8fa8ASCII\u7684\u3002\u4e00\u4e9b\u6269\u5c55\u62c9\u4e01\u5b57\u7b26\uff0c\u7528\u4e24\u4e2a\u5b57\u8282\u3002\uff08\u8fd9\u91cc\u7684\u4e24\u4e2a\u5b57\u8282\u5e76\u4e0d\u662f\u7b80\u5355\u7684\u548cUTF-16\u4e00\u6837\u7684\u4e24\u4e2a\u5b57\u8282\uff0c\u8fd9\u91cc\u6709\u4e00\u7cfb\u5217\u7684\u5b57\u8282\u4f4d\u53d8\u6362\u8c03\u7528\uff09\uff0c\u4e2d\u6587\u5b57\u7b26\u7528\u4e09\u4e2a\u5b57\u8282\uff0c\u4e00\u4e9b\u975e\u5e38\u5c11\u7528\u7684\u5b57\u7b26\u624d\u75284\u4e2a\u5b57\u8282\u3002\u7f3a\u70b9\uff1a\u627e\u5b57\u7b26\u7684\u7a7a\u95f4\u590d\u6742\u5ea6\u662fO(N)\uff1b\u8fd8\u6709\u5c31\u662f\u5b57\u8282\u4f4d\u53d8\u6362\u6240\u9700\u8981\u7684\u7f16\u89e3\u7801\u65f6\u95f4\u3002<\/span><\/p>\n

\uff086\uff09\u5728PYTHON3\u4e2d\u6240\u6709\u7684\u5b57\u7b26\u4e32\u90fd\u662fUNICODE\u5b57\u7b26\u4e32\uff0c\u4e0d\u7528\u5c06\u5b83\u4eec\u7279\u610f\u7684\u7f16\u7801\u6210UTF-8\u6216CP-l252\u3002UTF-8\u53ea\u662f\u4e00\u79cd\u7f16\u7801\u65b9\u5f0f\u3002<\/p>\n

\uff087\uff09python\u5b9a\u4e49\u5b57\u7b26\u4e32\u53ef\u4ee5\u4f7f\u7528\u5355\u5f15\u53f7\uff08’\uff09\u6216\u53cc\u5f15\u53f7\uff08’\uff09\uff0c\u5b57\u7b26\u4e32\u53ef\u4ee5\u50cflist\u4e00\u6837\u901a\u8fc7\u7d22\u5f15\u53cd\u56de\u5b57\u4e32\u4e2d\u7684\u5355\u4e2a\u5b57\u7b26\uff0c\u540c\u6837\u53ef\u4ee5\u50cflist\u7684\u4e00\u6837\u4f7f\u7528\u52a0\u53f7\uff08+\uff09\u8fde\u63a5\u4e24\u4e2a\u5b57\u7b26\u53f7\u3002<\/p>\n

\uff088\uff09python3\u652f\u6301\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\uff0c\u5176\u57fa\u672c\u7528\u6cd5\u662f\u5728\u4e00\u4e2a\u5b57\u7b26\u4e32\u4e2d\u63d2\u5165\u5360\u4f4d\u7b26\u5982\uff1a
\n>>>\u201c{0}’s password is {1}”.format(username, password)#{0}\u548c{1}\u90fd\u662f\u88ab\u66ff\u6362\u7684\u5b57\u6bb5\uff0c\u8fd9\u91cc\u7684\u6574\u65700\u548c1\u7528\u4e8e\u6307\u793aformat\u4e2d\u7684\u4f4d\u7f6e\u53c2\u6570\u3002
\n>>>si_suffixes = [ ‘KB’, ‘MB’, ‘GB’, ‘TB’, ‘PB’, ‘EB’, ‘ZB’, ‘YB’]
\n>>>’1000{0[0]}=1{0[1]}’.format(si_suffixes)
\n‘1000KB = 1MB’
\n\u56e0\u4e3a0\u6307\u5411\u5bf9\u50cfsi_suffixes\uff0c\u800csisuffixes\u662f\u4e00\u4e2alist\uff0c\u90a3\u4e48list\u662f\u53ef\u4ee5\u4f7f\u7528\u7d22\u5f15\u6307\u5411\u5176\u4e2d\u7684\u5143\u7d20\u7684\u3002<\/p>\n

\uff089\uff09'{0:.1f}{1}’.format(698.24,\u00a0 ‘GB’)\uff0c\u8fd9\u4e2a\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\u4e2d”:.1f”\u662f\u683c\u5f0f\u6307\u793a\u7b26\uff0c\u7528\u6765\u8fdb\u4e00\u6b65\u7cbe\u786e\u5b9a\u4e49\u5b57\u4e32\u683c\u5f0f\u3002\u683c\u5f0f\u6307\u793a\u7b26\u5fc5\u987b\u4ee5\u5192\u53f7\u5f00\u5934\uff08:\uff09\u3002\u8be6\u7ec6\u7684\u683c\u5f0f\u5316\u5b57\u7b26\u5185\u5bb9\uff1ahttps:\/\/docs.python.org\/3.1\/library\/string.html#format-specification-mini-language<\/span><\/span><\/p>\n

\uff0810\uff09\u5176\u5b83\u683c\u5f0f\u5316\u51fd\u6570\uff1a
\n1\uff09s.upper()#\u5b57\u7b26\u4e32\u5927\u5199
\n2\uff09s.lower()#\u5b57\u7b26\u4e32\u5c0f\u5199
\n3\uff09s.count(substr)#\u7edf\u8ba1\u5b50\u4e32\u6570\u91cf
\n4\uff09s.split(ampersand)#\u5c06\u5b57\u7b26\u4e32\u6839\u636eampersand\u5b57\u7b26\u5206\u6210\u51e0\u4e2a\u4e32\uff0c\u8fd4\u56de\u4e00\u4e2a\u5b57\u7b26\u4e32\u5217\u8868\uff0c\u5b83\u6709\u4e00\u4e2a\u53ef\u9009\u7684\u7b2c\u4e8c\u4e2a\u53c2\u6570\uff0c\u7528\u4e8e\u6307\u5b9a\u5b57\u7b26\u4e32\u5206\u5272\u51e0\u6b21\u3002
\n5\uff09\u5b57\u7b26\u4e32\u5206\u7247\uff0cs[start:end]\u3002\u5f97\u5230\u5b57\u7b26\u4e32s\u4ee5start\u5f00\u59cb\uff0c\u4ee5end\u7ed3\u675f\uff08\u4e0d\u5305\u542b\uff09<\/p>\n

\uff0811\uff09\u4e00\u4e2a\u4e0d\u53ef\u4fee\u6539\u7684unicode\u5b57\u7b26\u5e8f\u5217\u79f0\u4f5cstr\u3002\u4e00\u4e2a\u4e0d\u53ef\u4fee\u6539\u7684\u5e8f\u5217\uff08\u6570\u5b57\u57280~255\u4e4b\u95f4\uff0c\\x00\u5230\\xff\uff09\u79f0\u4f5cbytes\u3002
\n>>>by = b’abcd\\x65′
\nb’abcde’
\n>>>len(by)
\n5
\n\u4ee3\u8868by\u67095\u4e2a\u5b57\u8282\u957f\u5ea6<\/p>\n

\uff0812\uff09bytes\u5bf9\u8c61\u662f\u4e0d\u53ef\u4ee5\u4fee\u6539\u5185\u5bb9\u7684\uff0c\u5982\u679c\u8981\u4fee\u6539\uff0c\u6709\u4e24\u4e2a\u65b9\u6cd5\uff1a
\n1\uff09\u5f97\u5230\u5b57\u7b26\u4e32\u7684\u7247\u65ad\u7136\u540e\u91cd\u7ec4\u6210\u65b0\u7684bytes\u3002
\n2\uff09\u628abytes\u5bf9\u8c61\u8f6c\u6362\u6210bytearray\u5bf9\u8c61\uff0c\u4e4b\u540e\u518d\u7528bytes()\u51fd\u6570\u8f6c\u6362\u6210bytes\uff1a
\n>>> by = b’abcd\\x65′
\n>>> barr = bytearray(by)
\n>>> barr
\nbytearray(b’abcde’)
\n>>> len(barr)
\n5
\n>>> barr[0] = 102
\n>>> barr
\nbytearray(b’fbcde’)
\n>>> by = bytes(barr)
\n>>>by
\nb’fbcde’<\/p>\n

\uff0813\uff09bytes\u548cstr\u4e24\u4e2a\u7c7b\u578b\u4e0d\u53ef\u4ee5\u6df7\u7528\uff0c\u5982\uff1a
\n>>> by = b’d’
\n>>> s=’abcde’
\n>>> by+s
\nTraceback (most recent call last):
\nFile “<stdin>”, line 1, in <module>
\nTypeError: can’t concat bytes to str<\/p>\n

\uff0814\uff09bytes\u5bf9\u8c61\u6709decode()\u65b9\u6cd5\uff0c\u5b83\u53ef\u4ee5\u5bf9\u5b57\u7b26\u8fdb\u884c\u7f16\u7801\u5e76\u8fd4\u56de\u5b57\u7b26\u4e32\u3002\u5e76\u4e14\u5b57\u7b26\u4e32(str)\u6709encode()\u65b9\u6cd5\uff0c\u5b83\u53ef\u4ee5\u5bf9\u5b57\u7b26\u8fdb\u884c\u7f16\u7801\u5e76\u8fd4\u56debytes\u5bf9\u8c61\u3002
\n>>>s.count(by.decode(‘ascii’))#\u5c06bytes\u5e8f\u5217\u7528ASCII\u7f16\u7801\u8f6c\u6362\u6210\u5b57\u7b26\u4e32\uff0c\u7136\u540e\u7edf\u8ba1\u8be5\u4e32\u5728s\u4e2d\u51fa\u73b0\u8fc7\u51e0\u6b21\u3002>>> a_string = ‘\u6df1\u5165 Python’ \u2460
\n>>> len(a_string)
\n9
\n>>> by = a_string.encode(‘utf-8′) \u2461
\n>>> by
\nb’\\xe6\\xb7\\xb1\\xe5\\x85\\xa5 Python’
\n>>> len(by)
\n13
\n>>> by = a_string.encode(‘gb18030′) \u2462
\n>>> by
\nb’\\xc9\\xee\\xc8\\xeb Python’
\n>>> len(by)
\n11
\n>>> by = a_string.encode(‘big5′) \u2463
\n>>> by
\nb’\\xb2`\\xa4J Python’
\n>>> len(by)
\n11
\n>>> roundtrip = by.decode(‘big5’) \u2464
\n>>> roundtrip
\n‘\u6df1\u5165 Python’
\n>>> a_string == roundtrip
\nTrue<\/p>\n

\uff0815\uff09python3\u5047\u5b9a\u4f60\u7684\u6e90\u7a0b\u5e8f\u6587\u4ef6\u2014\u2014.py\u6587\u4ef6\uff0c\u4f7f\u7528UTF-8\u7f16\u7801\u683c\u5f0f\u3002\uff08python2\u7684.py\u6587\u4ef6\u9ed8\u8ba4\u7f16\u7801\u662fASCII\uff09\u53ef\u4ee5\u624b\u52a8\u8bbe\u5b9a\u6587\u4ef6\u7684\u7f16\u7801\u683c\u5f0f\uff0c\u5728\u6587\u4ef6\u7684\u7b2c\u4e00\u884c\u5199\uff1a
\n#-*- coding: windows-l252 -*-
\n\u6307\u5b9a\u6587\u4ef6\u7684\u7f16\u7801\u683c\u5f0f\u4e3awindows-l252\uff0c\u6280\u672f\u4e0a\u8bb2\u4e5f\u53ef\u4ee5\u662f\u7b2c\u4e8c\u884c\uff0c\u5982\u679c\u7b2c\u4e00\u884c\u662fUNIX-LIKE hash-bang\u547d\u4ee4\u3002
\n#!\/usr\/bin\/python3
\n#-*- coding: windows-l252 -*-<\/p>\n

\uff0816\uff09str.join(list)\u5c06\u5b57\u7b26\u4e32\u8fde\u63a5\u8d77\u6765\uff0c\u7528str\u5206\u9694\u6bcf\u4e2a\u5b57\u7b26\u4e32\u3002
\n>>> words = [‘SEND’, ‘MORE’, ‘MONEY’]
\n>>> ‘hi’.join(words)
\n‘SENDhiMOREhiMONEY’<\/p>\n","protected":false},"excerpt":{"rendered":"

\uff081\uff09\u6bcf\u4e2aUNICODE\u5b57\u7b264\u5b57\u8282\u5927\u5c0f\uff0c\u53ef\u4ee5\u7528UNICODE\u63cf\u8ff0\u6bcf\u79cd\u8bed\u8a00\u7684\u6bcf\u4e00\u4e2a\u5b57\u7b26\uff0c\u65e0\u8bba\u5f53\u524d\u8bed\u8a00\u6709\u6ca1\u6709\u201cA\u201d\u8fd9\u4e2a\u5b57\u7b26\uff0cU+0041\u8fd9\u4e2aUNICODE\u4ee3\u7801\u90fd\u4ee3\u8868…<\/p>\n

Read More Read More<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-55","post","type-post","status-publish","format-standard","hentry","category-dive-into-python3"],"_links":{"self":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/55","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=55"}],"version-history":[{"count":11,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/55\/revisions"}],"predecessor-version":[{"id":123,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/55\/revisions\/123"}],"wp:attachment":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=55"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=55"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=55"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}