{"id":167255,"date":"2020-10-11T16:44:54","date_gmt":"2020-10-11T08:44:54","guid":{"rendered":"http:\/\/4563.org\/?p=167255"},"modified":"2020-10-15T15:38:23","modified_gmt":"2020-10-15T07:38:23","slug":"python-%e4%b8%ba%e4%bb%80%e4%b9%88%e4%b8%8d%e6%94%af%e6%8c%81-switch-%e8%af%ad%e5%8f%a5%ef%bc%9f","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=167255","title":{"rendered":"Python \u4e3a\u4ec0\u4e48\u4e0d\u652f\u6301 switch \u8bed\u53e5\uff1f"},"content":{"rendered":"
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Python \u4e3a\u4ec0\u4e48\u4e0d\u652f\u6301 switch \u8bed\u53e5\uff1f <\/h1>\n

<\/p>\n

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\u8cc7\u6df1\u5927\u4f6c : chinesehuazhou <\/span> <\/i> 7<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n

\u5206\u4eab\u4e00\u7bc7\u6587\u7ae0<\/p>\n

\n

\u672c\u6587\u51fa\u81ea\u201cPython \u4e3a\u4ec0\u4e48\u201d\u7cfb\u5217\uff0c\u8bf7\u67e5\u770b\u5168\u90e8\u6587\u7ae0<\/p>\n<\/blockquote>\n

\u5728\u8fd9\u7bc7\u6587\u7ae0\u91cc\uff0c\u6211\u4eec\u4f1a\u804a\u4e00\u804a\u4e3a\u4ec0\u4e48 Python \u51b3\u5b9a\u4e0d\u652f\u6301 switch \u8bed\u53e5\u3002<\/p>\n

\u4e3a\u4ec0\u4e48\u60f3\u8981\u804a\u8fd9\u4e2a\u8bdd\u9898\u5462\uff1f<\/p>\n

\u4e3b\u8981\u662f\u56e0\u4e3a switch \u5728\u5176\u5b83\u8bed\u8a00\u4e2d\u592a\u5e38\u89c1\u4e86\uff0c\u800c Python \u5374\u4e0d\u652f\u6301\uff0c\u8fd9\u6837\u7684\u72ec\u7279\u6027\u672c\u8eab\u5c31\u503c\u5f97\u5173\u6ce8\uff0c\u800c\u56de\u7b54\u8fd9\u4e2a\u95ee\u9898\uff0c\u4e5f\u80fd\u66f4\u52a0\u770b\u6e05 Python \u5728\u7a0b\u5e8f\u8bbe\u8ba1\u4e0a\u7684\u7406\u5ff5\uff0c\u4e86\u89e3 Python \u5728\u8bed\u6cd5\u8bbe\u8ba1\u4e2d\u7684\u51b3\u7b56\u8fc7\u7a0b\u3002<\/p>\n

\u672c\u6587\u9664\u4e86\u4f1a\u8be6\u7ec6\u5206\u6790 PEP-275 \u548c PEP-3103\uff0c\u8fd8\u4f1a\u4ecb\u7ecd\u5230 Python \u6700\u65b0\u7684\u53d1\u5c55\u52a8\u6001\uff08 PEP-622 \uff09\uff0c\u5373\u53ef\u80fd\u8981\u5f15\u5165\u7684\u6a21\u5f0f\u5339\u914d\uff08 pattern matching \uff09\u8bed\u6cd5\uff0c\u76f8\u4fe1\u8fd9\u4e2a\u8bdd\u9898\u4f1a\u5f00\u9614\u5927\u5bb6\u7684\u773c\u754c\uff0c\u4ece\u800c\u5bf9 switch \u8bed\u6cd5\u6709\u66f4\u4e3a\u5168\u9762\u7684\u8ba4\u8bc6\u3002<\/p>\n

1 \u3001switch \u662f\u4ec0\u4e48\uff1f<\/h2>\n

\u5728\u5f00\u59cb\u6b63\u9898\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u5148\u804a\u804a switch \u662f\u4ec0\u4e48\uff1f<\/p>\n

\u6709\u4e9b\u540c\u5b66\u53ef\u80fd\u4f1a\u7b2c\u4e00\u65f6\u95f4\u60f3\u5230\u5b83\u2026\u2026<\/p>\n

\"Python<\/p>\n

\u5582~\u5582~\uff0c\u9ebb\u70e6\u6536\u6536\u5fc3\uff0c\u522b\u603b\u60f3\u7740\u6e38\u620f\u5566\uff0c\u6211\u4eec\u8981\u8bf4\u7684\u662f\u7f16\u7a0b\u8bed\u8a00\u4e2d\u7684 switch \u8bed\u53e5\u3002<\/p>\n

\u4e00\u822c\u800c\u8a00\uff0cswitch \u7684\u8bed\u6cd5\u683c\u5f0f\u5982\u4e0b\uff1a<\/p>\n

switch(expression){     case value1:        \/\/ \u8bed\u53e5        break; \/\/ \u53ef\u9009     case value2:        \/\/ \u8bed\u53e5        break; \/\/ \u53ef\u9009     default: \/\/ \u53ef\u9009        \/\/ \u8bed\u53e5 } <\/code><\/pre>\n
\u4f7f\u7528\u6d41\u7a0b\u56fe\u6765\u8868\u793a\uff0c\u5927\u6982\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n
\"Python<\/p>\n
\u5b83\u7684\u7528\u6cd5\u4e0d\u96be\u7406\u89e3\uff1aswitch \u8bed\u53e5\u7684\u503c\u6ee1\u8db3\u54ea\u4e00\u4e2a case \u60c5\u51b5\uff0c\u5c31\u4f1a\u6267\u884c\u5bf9\u5e94\u7684\u4ee3\u7801\u5757\uff0c\u6267\u884c\u65f6\u9047\u5230 break \u5c31\u8df3\u51fa\uff0c\u5426\u5219\u5c31\u7ee7\u7eed\u6267\u884c\u4e0b\u4e00\u4e2a case \u5206\u652f\uff1b\u4e00\u822c\u4f1a\u5728\u6700\u540e\u653e\u4e00\u4e2a default \u5206\u652f\uff0c\u4f5c\u4e3a\u515c\u5e95\u3002<\/p>\n
\u5927\u591a\u6570\u8bed\u8a00\u90fd\u63d0\u4f9b\u4e86 switch \u8bed\u53e5\u6216\u8005\u6781\u5176\u76f8\u4f3c\u7684\u4e1c\u897f\uff0c\u4f8b\u5982\uff0c\u5728 C\/C++\/Java \/Go \u7b49\u9759\u6001\u8bed\u8a00\u4e2d\uff0c\u5b83\u4eec\u90fd\u652f\u6301 switch-case \u7ed3\u6784\uff1b\u5728 Ruby \u4e2d\u6709\u7c7b\u4f3c\u7684 case-when \u7ed3\u6784\uff0c\u5728 Shell \u8bed\u8a00\u4e2d\uff0c\u6709\u76f8\u4f3c\u7684 case-in \u7ed3\u6784\uff0c\u5728 Perl \u4e2d\uff0c\u6709 switch-case-else\u2026\u2026<\/p>\n
switch \u8bed\u53e5\u7684\u597d\u5904\u662f\u652f\u6301\u201c\u5355\u6761\u4ef6\u591a\u5206\u652f\u201d\u7684\u9009\u62e9\u7ed3\u6784\uff0c\u76f8\u6bd4 if-else \u7684\u4e8c\u5206\u9009\u62e9\u7ed3\u6784\uff0c\u5728\u67d0\u4e9b\u65f6\u5019\u4f1a\u66f4\u4e3a\u7b80\u6d01\u6e05\u6670\u3002<\/p>\n
\u4f46\u662f\uff0c\u5728 Python \u4e2d\uff0c\u6211\u4eec\u770b\u4e0d\u5230 switch-case \u6216\u8005\u76f8\u8fd1\u7684\u8bed\u6cd5\u7ed3\u6784\uff0c\u8fd9\u662f\u4e3a\u4ec0\u4e48\u5462\uff1f<\/p>\n
2 \u3001Python \u4e3a\u4ec0\u4e48\u4e0d\u652f\u6301 switch?<\/h2>\n
\u5b98\u65b9\u6587\u6863\u4e2d\u6709\u4e00\u7bc7 FAQ \u5305\u542b\u4e86\u8fd9\u4e2a\u95ee\u9898\uff1aWhy isn\u2019t there a switch or case statement in Python?<\/p>\n
\"Python<\/p>\n
\n
FAQ \u5373 Frequently Asked Questions \u7684\u7f29\u5199\uff0c\u8868\u793a\u5e38\u89c1\u95ee\u9898\uff0c\u5b98\u65b9\u5217\u4e86 27 \u4e2a\u5e38\u89c1\u95ee\u9898\uff0c\u5b8c\u6574\u6e05\u5355\u5728\u6b64\uff1ahttps:\/\/mp.weixin.qq.com\/s\/zabIvt4dfu_rf7SmGZXqXg<\/p>\n<\/blockquote>\n
\u8be5\u6587\u6863\u7ed9\u51fa\u4e86\u51e0\u4e2a\u5efa\u8bae\uff0c\u544a\u8bc9\u4e86\u6211\u4eec\u51e0\u4e2a switch\/case \u7684\u66ff\u4ee3\u65b9\u6848\uff1a<\/p>\n
    \n
  • \u4f7f\u7528 if-elif-else \u6761\u4ef6\u5224\u65ad\u8bed\u53e5<\/li>\n
  • \u4f7f\u7528\u5b57\u5178\uff0c\u5c06 case \u503c\u4e0e\u8c03\u7528\u7684\u51fd\u6570\u6620\u5c04\u8d77\u6765<\/li>\n
  • \u4f7f\u7528\u5185\u7f6e getattr() \u68c0\u7d22\u7279\u5b9a\u7684\u5bf9\u8c61\u8c03\u7528\u65b9\u6cd5<\/li>\n<\/ul>\n
    \u66fe\u6709\u4eba\u63d0\u51fa\u8fc7\u4e00\u4e9b\u63d0\u6848\uff08\u5373 PEP-275 \u548c PEP-3103 \uff09\uff0c\u60f3\u7ed9 Python \u5f15\u5165 switch \u8bed\u6cd5\uff0c\u7136\u800c\uff0c\u5bf9\u4e8e\u201c\u662f\u5426\u4ee5\u53ca\u5982\u4f55\u8fdb\u884c\u9776\u573a\u6d4b\u8bd5<\/strong>\u201d\uff0c\u5927\u5bb6\u6ca1\u6709\u8fbe\u6210\u4e00\u81f4\u7684\u5171\u8bc6\u3002<\/p>\n
    \u9776\u573a\u6d4b\u8bd5\uff0c\u5373 range test\uff0c\u6307\u7684\u662f\u5bf9\u6b66\u5668\u5f39\u836f\u7684\u6280\u672f\u6027\u80fd\u4f5c\u5404\u79cd\u6d4b\u8bd5\u9a8c\u8bc1\uff0c\u4e0e\u836f\u7269\u7684\u4e34\u5e8a\u8bd5\u9a8c\u4e00\u6837\uff0c\u90fd\u662f\u5728\u6700\u7ec8\u4ea7\u54c1\u4ea4\u4ed8\u524d\u7684\u4e00\u9879\u5173\u952e\u6027\u6d4b\u8bd5\u3002<\/p>\n
    \u5b98\u65b9\u6587\u6863\u5bf9\u4e8e\u201c\u4e3a\u4ec0\u4e48 Python \u4e0d\u5f15\u5165 switch\u201d\u7684\u89e3\u91ca\uff0c\u5b9e\u9645\u4e0a\u6765\u6e90\u4e8e Python \u4e4b\u7236 Guido van Rossum \u5728 PEP-3103 \u4e2d\u7684\u610f\u89c1\uff1a<\/p>\n
    \"Python<\/p>\n
    \u51fa\u5904\uff1ahttps:\/\/www.python.org\/dev\/peps\/pep-3103\/<\/p>\n
    \n
    A quick poll during my keynote presentation at PyCon 2007 shows this proposal has no popular support. I therefore reject it.<\/p>\n
    \u6211\u5728 PyCon 2007 \u7684\u4e3b\u9898\u6f14\u8bb2\u4e2d\u505a\u4e86\u4e00\u4e2a\u5feb\u901f\u7684\u6c11\u610f\u8c03\u67e5\uff0c\u7ed3\u679c\u8868\u660e\u8fd9\u4e2a\u63d0\u6848\u6ca1\u6709\u5f97\u5230\u5e7f\u6cdb\u7684\u652f\u6301\u3002\u56e0\u6b64\uff0c\u6211\u62d2\u7edd\u4e86\u5b83\u3002<\/p>\n<\/blockquote>\n
    \u7b80\u800c\u8a00\u4e4b\uff0cPEP \u63d0\u6848\u6709\u4e86\uff0c\u8bed\u6cd5\u5b9e\u73b0\u4e5f\u6709\u4e86\u96cf\u5f62\uff0c\u4f46\u662f\u6838\u5fc3\u5f00\u53d1\u8005\u4eec\u4f3c\u4e4e\u6ca1\u6709\u8fbe\u6210\u4e00\u81f4\u610f\u89c1\uff0c\u6700\u7ec8\u5bfc\u81f4\u63d0\u6848\u6d41\u4ea7\u4e86\u3002<\/strong><\/p>\n
    3 \u3001PEP-275 \u4e0e PEP-3103 \u8bf4\u4e86\u4ec0\u4e48\uff1f<\/h2>\n
    PEP-3103 \u662f\u5728 2006 \u5e74\u63d0\u51fa\u7684\uff0cPEP-275 \u5219\u662f\u5728 2001 \u5e74\u63d0\u51fa\u7684\uff0c\u5b83\u4eec\u7684\u5171\u540c\u4e4b\u5904\u662f\u63d0\u51fa\u4e86\u5f15\u5165 switch \u8bed\u53e5\u7684\u67d0\u79cd\u5fc5\u8981\u6027\u3001\u5206\u6790\u4e86\u597d\u51e0\u79cd\u5907\u9009\u7684\u5b9e\u73b0\u65b9\u6848\uff0c\u7136\u800c\uff0c\u7ed3\u5c40\u662f\u90fd\u88ab\u62d2\u7edd\u4e86\u3002<\/p>\n
    \"Python<\/p>\n
    \u51fa\u5904\uff1ahttps:\/\/www.python.org\/dev\/peps\/pep-0275\/<\/p>\n
    \u90a3\u4e48\uff0c\u6211\u4eec\u5c31\u5148\u6765\u56de\u987e\u4e00\u4e0b\u6838\u5fc3\u5f00\u53d1\u8005\u4eec\u90fd\u505a\u51fa\u4e86\u54ea\u4e9b\u8ba8\u8bba\uff0c\u770b\u4e00\u770b\u5982\u679c Python \u8981\u5b9e\u73b0 switch \u7ed3\u6784\uff0c\u4f1a\u662f\u600e\u4e48\u6837\u5b50\u7684\uff1f\uff08 PS\uff1aPEP \u91cc\u8fd8\u6d89\u53ca\u5176\u5b83\u5185\u5bb9\uff0c\u672c\u6587\u53ea\u6458\u53d6\u4e0e switch \u76f4\u63a5\u76f8\u5173\u7684\u90e8\u5206\uff09<\/p>\n
    PEP-275 \u63d0\u51fa\u7684\u8bed\u6cd5\u7ed3\u6784\u5982\u4e0b\uff1a<\/p>\n
    switch EXPR:     case CONSTANT:         SUITE     case CONSTANT:         SUITE     ...     else:         SUITE <\/code><\/pre>\n
    \u5176\u4e2d else \u5206\u652f\u662f\u53ef\u9009\u7684\uff0c\u5982\u679c\u6ca1\u6709\u5b83\uff0c\u5e76\u4e14\u524d\u9762\u7684\u5206\u652f\u90fd\u4e0d\u6ee1\u8db3\u7684\u8bdd\uff0c\u5c31\u4ec0\u4e48\u4e5f\u4e0d\u505a\u3002\u53e6\u5916 case \u503c constant \u652f\u6301\u4e0d\u540c\u7c7b\u578b\uff0c\u56e0\u4e3a expr \u8868\u8fbe\u5f0f\u7684\u7c7b\u578b\u662f\u52a8\u6001\u7684\u3002<\/p>\n
    PEP-275 \u8fd8\u63d0\u51fa\u8ba9 switch \u4e0d\u652f\u6301\u6389\u843d\uff08 fall-through \uff09\u884c\u4e3a\uff0c\u5373\u6bcf\u4e2a case \u5206\u652f\u76f8\u4e92\u72ec\u7acb\u800c\u5b8c\u6574\uff0c\u4e0d\u7528\u50cf C \u8bed\u8a00\u90a3\u6837\u9700\u8981\u5199 break \u3002<\/p>\n
    \u8be5 PEP \u8fd8\u5217\u4e3e\u4e86\u4e00\u4e9b\u5176\u5b83\u7684 issue\uff1a<\/p>\n
      \n
    • \u91cd\u7528\u73b0\u6709\u5173\u952e\u5b57\uff0c\u4e0d\u5f15\u5165\u201cswitch\u201d\u548c\u201ccase\u201d<\/li>\n
    • \u4f7f\u7528\u65b0\u7684\u5173\u952e\u5b57\uff0c\u907f\u514d\u4e0e C \u7684 switch \u6982\u5ff5\u6df7\u6dc6<\/li>\n
    • \u652f\u6301\u5355\u5206\u652f\u591a\u503c\u9009\u62e9\uff08\u4f8b\u5982\uff1acase ‘a’, ‘b’, ‘c’: …\uff09<\/li>\n
    • \u8fd8\u6709\u5efa\u8bae\u652f\u6301\u8303\u56f4\u53d6\u503c\u5224\u65ad\uff08\u4f8b\u5982\uff1acase 10..14: …\uff09<\/li>\n<\/ul>\n
      \u9664\u4e86\u9996\u9009\u65b9\u6848\uff0c\u8be5 PEP \u8fd8\u8bb0\u5f55\u4e86\u51e0\u79cd\u98ce\u683c\u5404\u5f02\u7684\u8bed\u6cd5\u65b9\u6848\uff1a<\/p>\n
      case EXPR:     of CONSTANT:         SUITE     of CONSTANT:         SUITE     else:         SUITE  case EXPR:     if CONSTANT:          SUITE     if CONSTANT:         SUITE     else:         SUITE  when EXPR:     in CONSTANT_TUPLE:         SUITE     in CONSTANT_TUPLE:         SUITE     ... else:      SUITE <\/code><\/pre>\n
      PEP-275 \u8bb0\u5f55\u4e0b\u4e86\u4e0d\u5c11\u91cd\u8981\u7684\u601d\u8def\u548c\u95ee\u9898\uff0c\u4e3a PEP-3103 \u7684\u51fa\u73b0\u505a\u4e86\u5f88\u597d\u7684\u94fa\u57ab\u3002<\/p>\n
      \u90a3\u4e48\uff0c\u6211\u4eec\u518d\u6765\u770b\u770b\u7531 Guido \u7f16\u5199\u7684 PEP-3103 \u8bf4\u4e86\u4e9b\u4ec0\u4e48\u5427\u3002<\/p>\n
      \u5b83\u9996\u5148\u8ba4\u53ef\u4e86 PEP-275 \u4e2d\u7684\u4e24\u4e2a\u57fa\u7840\u8bbe\u5b9a\uff0c\u4f8b\u5982\uff0c\u5b9e\u73b0\u201c\u9690\u5f0f\u7684 break\u201d\uff0c\u4e0d\u8ba9 case \u5206\u652f\u51fa\u73b0 fall-through \u8fd9\u79cd\u8f6c\u79fb\u63a7\u5236\u6743\u7684\u60c5\u51b5\uff08\u5176\u5b83\u8bed\u8a00\u4f3c\u4e4e\u90fd\u8981\u6c42\u663e\u5f0f\u5730\u5199 break \uff09\uff1b else \u5206\u652f\u662f\u53ef\u9009\u7684\uff0c\u590d\u7528 else \u5173\u952e\u5b57\uff0c\u800c\u4e0d\u7528\u5f15\u5165\u201cdefault\u201d\u3002<\/p>\n
      \u5bf9\u4e8e PEP-275 \u63d0\u5021\u7684\u90a3\u79cd\u98ce\u683c\uff0cGuido \u6bd4\u8f83\u8ba4\u53ef\uff0c\u4f46\u4e5f\u8ba4\u4e3a\u5b83\u7684\u95ee\u9898\u662f\u7f29\u8fdb\u5c42\u6b21\u592a\u591a\uff0c\u56e0\u6b64\u5efa\u8bae\u51cf\u5c11\u4ee3\u7801\u5206\u652f\u7f29\u8fdb\u7684\u7a7a\u683c\u6570\uff0c\u4f8b\u5982\u672c\u6765\u7f29\u8fdb 4 \u7a7a\u683c\uff0c\u6539\u4e3a\u7f29\u8fdb 2 \u7a7a\u683c\u3002<\/p>\n
      PEP-3103 \u8fd8\u5217\u4e3e\u4e86\u53e6\u5916\u4e09\u79cd\u5b9e\u73b0\u65b9\u6848\uff0c\u5206\u6790\u4e86\u5b83\u4eec\u7684\u5dee\u5f02\u4ee5\u53ca\u95ee\u9898\uff0c\u5177\u4f53\u5185\u5bb9\u4ece\u7565\uff0c\u8fd9\u91cc\u53ea\u7ed9\u5927\u5bb6\u770b\u770b\u5b83\u4eec\u7684\u98ce\u683c\uff1a<\/p>\n
      # case \u5206\u652f\u4e0d\u7f29\u8fdb switch EXPR: case EXPR:     SUITE case EXPR:     SUITE .... else:     SUITE  # switch \u8bed\u53e5\u540e\u4e0d\u52a0\u5192\u53f7 switch EXPR case EXPR:     SUITE case EXPR:     SUITE .... else:     SUITE  # \u7701\u7565 case \u5173\u952e\u5b57 switch EXPR:     EXPR:         SUITE     EXPR:         SUITE     ...     else:         SUITE <\/code><\/pre>\n
      \u5728\u57fa\u7840\u8bed\u6cd5\u4e4b\u5916\uff0cGuido \u82b1\u4e86\u5f88\u591a\u7bc7\u5e45\u6765\u8ba8\u8bba\u6269\u5c55\u8bed\u6cd5\uff08 Extended Syntax \uff09\uff0c\u5373\u5728\u4e00\u4e2a case \u5206\u652f\u4e2d\u5b9e\u73b0\u5339\u914d\u591a\u4e2a\u503c\u7684\u590d\u6742\u60c5\u51b5\uff1a<\/p>\n
      case EXPR, EXPR, ...:  # Guido \u4f18\u9009\u7684 case in EXPR_LIST:  case *EXPR:  case [*]EXPR, [*]EXPR, ...:  case *(EXPR, EXPR, ...): <\/code><\/pre>\n
      \u4ed6\u91cd\u70b9\u8003\u8651\u5230\u7684\u95ee\u9898\u5305\u62ec\uff1aswitch \u4e2d\u8868\u8fbe\u5f0f\u7684\u7ed3\u679c\u662f\u5143\u7ec4\u6216\u53ef\u8fed\u4ee3\u5bf9\u8c61\u7684\u60c5\u51b5\u3001case \u7684\u503c\u88ab\u770b\u6210\u5143\u7ec4\u89e3\u5305\u7684\u60c5\u51b5\u3001\u5728 case \u5206\u652f\u4f5c\u201c*\u201d\u661f\u53f7\u64cd\u4f5c\u2026\u2026<\/p>\n
      \u63a5\u7740\uff0cGuido \u53c8\u7528\u4e86\u975e\u5e38\u975e\u5e38\u591a\u7684\u7bc7\u5e45\u6765\u5206\u6790\u8be5\u5982\u4f55\u5b9e\u73b0 switch\uff0c\u5176\u4e2d\u8ba8\u8bba\u5230\u7684\u4e3b\u8981\u601d\u8def\u6709\uff1a<\/p>\n
        \n
      • \u4f7f\u7528\u7b49\u4ef7\u7684 if-elif \u94fe\u6765\u5b9a\u4e49 switch \u8bed\u53e5\uff08\u53ef\u80fd\u4f1a\u505a\u4e9b\u4f18\u5316\uff09<\/li>\n
      • \u540c\u4e0a\uff0c\u53e6\u5916\u6240\u6709\u8868\u8fbe\u5f0f\u90fd\u5fc5\u987b\u662f\u53ef\u54c8\u5e0c\u7684\uff08 hashable \uff09<\/li>\n
      • \u770b\u4f5c\u662f\u9884\u5148\u8ba1\u7b97\u7684\u5b57\u5178\u7684\u5206\u6d3e\uff08 dispatch \uff09<\/li>\n<\/ul>\n
        PEP \u4e2d\u8fd9\u90e8\u5206\u7684\u5185\u5bb9\u975e\u5e38\u591a\uff0c\u56e0\u4e3a\u5728\u6bcf\u4e2a\u601d\u8def\u4e0a\uff0cGuido \u8fd8\u8003\u8651\u5230\u4e86\u597d\u51e0\u79cd\u5b9e\u73b0\u8def\u5f84\uff0c\u8fd9\u5bfc\u81f4\u4e86\u4ed6\u5728\u590d\u6742\u5206\u6790\u540e\u7684\u7ed3\u8bba\u662f\uff1aIt is too early to decide \uff08 \u73b0\u5728\u505a\u51b3\u5b9a\u4e3a\u65f6\u5c1a\u65e9\uff09\u3002<\/p>\n
        \u9605\u8bfb\u5b8c PEP-3103 \u540e\uff0c\u6211\u603b\u4f53\u7684\u611f\u89c9\u662f\uff1aGuido \u7684\u601d\u8def\u975e\u5e38\u53d1\u6563\u3001\u5c42\u6b21\u4e30\u5bcc\uff0c\u4f46\u662f\uff0c\u7f3a\u5c11\u4e86\u4ed6\u5728\u9762\u5bf9\u5176\u5b83\u95ee\u9898\u65f6\u90a3\u201c\u5feb\u5200\u65a9\u4e71\u9ebb\u201d\u5f0f\u7684\u6d1e\u5bdf\u529b\u3002<\/p>\n
        \u4e5f\u5c31\u662f\u8bf4\uff0c\u5728\u8bf8\u591a\u7684\u53ef\u80fd\u6027\u65b9\u6848\u4e2d\uff0c\u4ed6\u529b\u6c42\u9762\u9762\u4ff1\u5230\uff0c\u6700\u7ec8\u65e0\u6cd5\u8bf4\u670d\u81ea\u5df1\u505a\u51fa\u4e00\u4e2a\u72ec\u88c1\u7684\u51b3\u5b9a\u3002\u963b\u529b\u4e3b\u8981\u6765\u81ea\u4e8e\u4ed6\u81ea\u5df1\uff0c\u800c\u4e0d\u662f\u5176\u4ed6\u4eba\u3002<\/p>\n
        \u4e0d\u8fc7\uff0c\u4e4b\u6240\u4ee5\u4f1a\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\uff0c\u4e5f\u8bb8\u8ddf\u4ed6\u7684\u9884\u8bbe\u7acb\u573a\u6709\u5173\uff1a\u4ed6\u4f3c\u4e4e\u8ba4\u4e3a\u201cPython is fine without a switch statement\u201d\uff0c\u56e0\u6b64\u5c3d\u7ba1\u5199\u4e86\u5f88\u957f\u7684 PEP\uff0c\u4f46\u53ea\u662f\u5728\u628a\u95ee\u9898\u590d\u6742\u5316\uff0c\u628a\u8bae\u9898\u6401\u7f6e\u8d77\u6765\u3002<\/p>\n
        \u6700\u540e\uff0c\u4ed6\u5728 PyCon \u4e0a\u505a\u4e86\u4e00\u4e2a\u5c0f\u8303\u56f4\u8c03\u67e5\uff0c\u501f\u6b64\u201c\u540d\u6b63\u8a00\u987a\u201d\u5730\u62d2\u7edd\u4e86\u81ea\u5df1\u53d1\u8d77\u7684 PEP\uff0c\u8bd5\u56fe\u5835\u4f4f\u4f17\u4eba\u7684\u60a0\u60a0\u4e4b\u53e3\u2026\u2026<\/p>\n
        4 \u3001\u672a\u6765\u4f1a\u6709 switch \u8bed\u53e5\u4e48\uff1f<\/h2>\n
        \u5f52\u7ed3\u8d77\u6765\uff0c\u4e4b\u6240\u4ee5 Python \u6ca1\u6709 switch \u8bed\u53e5\uff0c\u539f\u56e0\u6709\uff1aswitch \u7684\u5b9e\u73b0\u7ec6\u8282 \/\u529f\u80fd\u70b9\u672a\u7ecf\u6572\u5b9a\u3001\u6ca1\u6709 switch \u4e5f\u633a\u597d\u7684\u3001\u6709\u5176\u5b83\u4e0d\u9519\u7684\u65b9\u6cd5\u66ff\u4ee3 switch \u3001Guido \u7684\u5c0f\u4efb\u6027\u2026\u2026<\/strong><\/p>\n
        \u4f46\u662f\uff0c\u6211\u4eec\u8fd8\u662f\u8981\u8ffd\u95ee\u4e00\u53e5\uff1a\u672a\u6765\u4f1a\u6709 switch \u8bed\u53e5\u4e48\uff1f\u6216\u8005\u7c7b\u4f3c\u7684\u591a\u5206\u652f\u9009\u62e9\u7ed3\u6784\uff1f<\/strong><\/p>\n
        \u4e3a\u4ec0\u4e48\u8981\u6709\u6b64\u4e00\u95ee\u5462\uff1f\u539f\u56e0\u662f\u6709\u592a\u591a\u8bed\u8a00\u81ea\u5e26 switch \u8bed\u53e5\uff0c\u800c\u4e14\u4e5f\u6709\u5f88\u591a\u4eba\u5c1d\u8bd5\u7f16\u5199\u63d0\u4f9b switch \u529f\u80fd\u7684\u5e93\uff08\u6211\u8bb0\u5f97\u5728 PyCoder’s Weekly<\/em> \u91cc\u66fe\u89c1\u5230\u8fc7\u4e24\u6b21\uff09\u3002<\/p>\n
        \u6211\uff08 Python \u732b\uff09\u672c\u4eba\u81ea\u59cb\u81f3\u7ec8\u5e76\u4e0d\u559c\u6b22 switch\uff0c\u51e0\u4e4e\u53ef\u4ee5\u80af\u5b9a\u5730\u8bf4\uff0cPython \u672a\u6765\u4e5f\u4e0d\u4f1a\u6709 switch\uff0c\u4f46\u662f\uff0c\u5b83\u5f88\u53ef\u80fd\u4f1a\u5f15\u5165\u4e00\u4e2a\u7c7b\u4f3c\u4e8e switch \u4e14\u66f4\u4e3a\u590d\u6742\u7684\u8bed\u6cd5\u7ed3\u6784\uff01<\/p>\n
        2020 \u5e74 6 \u6708\uff0cPEP-622 \u88ab\u63d0\u51fa\u4e86\uff0c\u5b83\u5efa\u8bae\u5f15\u5165\u5728 Scala \u3001Erlang \u548c Rust \u7b49\u8bed\u8a00\u4e2d\u7684\u6a21\u5f0f\u5339\u914d\u8bed\u6cd5\uff08pattern matching<\/strong>\uff09\u3002<\/p>\n
        \"Python<\/p>\n
        \u622a\u81f3 2020 \u5e74 10 \u6708\uff0c\u8be5 PEP \u5df2\u88ab\u5206\u89e3\u6210\u53e6\u5916\u4e09\u4e2a PEP \uff08 634-636 \uff09\uff0c\u76ee\u524d\u90fd\u5904\u4e8e\u8349\u6848\u9636\u6bb5\u3002\u8003\u8651\u5230\u6838\u5fc3\u5f00\u53d1\u8005\u4eec\u7684\u53c2\u4e0e\u60c5\u51b5\u4ee5\u53ca\u8bdd\u9898\u8ba8\u8bba\u7684\u60c5\u51b5\uff0c\u8fd9\u4e9b\u63d0\u6848\u6781\u6709\u53ef\u80fd\u4f1a\u5728\u672a\u6765\u7248\u672c\uff08\u6bd4\u5982\u6b63\u5728\u5f00\u53d1\u4e2d\u7684 3.10 \uff09\u4e2d\u5b9e\u73b0\u3002<\/p>\n
        \u4ee5\u4e00\u4e2a\u6c42\u5e73\u5747\u6570\u7684\u51fd\u6570\u4e3a\u4f8b\uff0c\u6a21\u5f0f\u5339\u914d\u8bed\u6cd5\u53ef\u4ee5\u5b9e\u73b0\u6210\u8fd9\u6837\uff1a<\/p>\n
        def average(*args):     match args:         case [x, y]:           # captures the two elements of a sequence             return (x + y) \/ 2         case [x]:              # captures the only element of a sequence             return x         case []:             return 0         case x:                # captures the entire sequence             return sum(x) \/ len(x) <\/code><\/pre>\n
        match-case \u7ed3\u6784\u795e\u4f3c\u4e8e switch-case \u7ed3\u6784\uff0c\u7136\u800c\u5b83\u57fa\u4e8e\u6a21\u5f0f\uff08 pattern \uff09\u800c\u975e\u8868\u8fbe\u5f0f\uff08 expression \uff09\uff0c\u56e0\u6b64\u6709\u66f4\u591a\u5f85\u8003\u8651\u7684\u7ec6\u8282\u95ee\u9898\uff0c\u4e5f\u6709\u66f4\u4e3a\u5e7f\u9614\u7684\u5e94\u7528\u7a7a\u95f4\u3002<\/p>\n
        \u5bf9\u6b64\u8bdd\u9898\u611f\u5174\u8da3\u7684\u8bfb\u8005\uff0c\u5efa\u8bae\u53bb\u67e5\u9605\u8fd9\u51e0\u4e2a\u65b0\u7684 PEP \u3002<\/p>\n
        \u6700\u540e\uff0c\u8ba9\u6211\u4eec\u56de\u5230\u6807\u9898\u4e2d\u7684\u95ee\u9898\uff1aPython \u4e3a\u4ec0\u4e48\u4e0d\u652f\u6301 switch \u8bed\u53e5\uff1f<\/strong><\/p>\n
        \u5b98\u65b9\u6587\u6863\u7684 FAQ \u5bf9\u6b64\u95ee\u9898\u6709\u4e00\u4e2a\u89e3\u7b54\uff0c\u544a\u8bc9\u6211\u4eec\u6709\u51e0\u4e2a\u4e0d\u9519\u7684\u66ff\u4ee3\u5199\u6cd5\uff0c\u540c\u65f6\u4e5f\u7559\u4e0b\u4e86\u4e00\u6761\u7ebf\u7d22\uff1a\u66fe\u6709 PEP \u63d0\u8bae\u5f15\u5165 switch\uff0c\u53ea\u662f\u6ca1\u6709\u6210\u529f\u5b9e\u73b0\u3002<\/p>\n
        \u6cbf\u7740\u8fd9\u6761\u7ebf\u7d22\uff0c\u672c\u6587\u62c6\u89e3\u4e86 PEP-275 \u548c PEP-3103 \u8fd9\u4e24\u7bc7\u6587\u6863\uff0c\u5e26\u5927\u5bb6\u770b\u5230\u4e86 Python \u793e\u533a\u91cc\u63d0\u51fa\u8fc7\u7684\u98ce\u683c\u5404\u5f02\u7684 switch \u65b9\u6848\uff0c\u4ee5\u53ca\u8bf8\u591a\u7684\u60ac\u800c\u672a\u51b3\u7684\u95ee\u9898\u3002<\/p>\n
        \u6700\u540e\uff0c\u6211\u4eec\u8fd8\u5173\u6ce8\u5230\u4e86\u6700\u65b0\u7684 PEP-622 \u7684\u52a8\u6001\uff0c\u770b\u8d77\u6765 switch \u7684\u201c\u5b6a\u751f\u5144\u5f1f\u201d match \u8bed\u6cd5\u6709\u671b\u5f15\u5165\u5230 Python \u4e2d\uff01 switch \u8bdd\u9898\u7684\u8ba8\u8bba\u4f3c\u4e4e\u8981\u7ec8\u6b62\u4e86\uff0c\u4f46\u662f\u53e6\u4e00\u4e2a\u66f4\u5927\u7684\u8bdd\u9898\u6b63\u5728\u8fdb\u884c\u4e2d\uff01<\/p>\n
        \u672c\u6587\u5c5e\u4e8e\u201cPython \u4e3a\u4ec0\u4e48\u201d\u7cfb\u5217\uff08 Python \u732b\u51fa\u54c1\uff09\uff0c\u8be5\u7cfb\u5217\u4e3b\u8981\u5173\u6ce8 Python \u7684\u8bed\u6cd5\u3001\u8bbe\u8ba1\u548c\u53d1\u5c55\u7b49\u8bdd\u9898\uff0c\u4ee5\u4e00\u4e2a\u4e2a\u201c\u4e3a\u4ec0\u4e48\u201d\u5f0f\u7684\u95ee\u9898\u4e3a\u5207\u5165\u70b9\uff0c\u8bd5\u7740\u5c55\u73b0 Python \u7684\u8ff7\u4eba\u9b45\u529b\u3002\u6240\u6709\u6587\u7ae0\u5c06\u4f1a\u5f52\u6863\u5728 Github \u4e0a\uff0c\u6b22\u8fce\u5927\u5bb6\u7ed9\u9897\u5c0f\u661f\u661f\uff0c\u9879\u76ee\u5730\u5740\uff1a https:\/\/github.com\/chinesehuazhou\/python-whydo<\/p>\n<\/p><\/div>\n
         \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (3<\/span>)        <\/div>\n
         <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
          \n
        • \n
          \n
          \n
           \u8cc7\u6df1\u5927\u4f6c : black11black <\/span>  <\/div>\n
           <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                       \u4e0d\u7528\u5206\u6790\u90a3\u4e48\u591a\u6ca1\u7528\u7684\uff0c
          \u5efa\u8bae\u91cd\u8bfb python \u4e4b\u7985
          \u201cThere should be one– and preferably only one –obvious way to do it.\u201d                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
        • \n
          \n
          \n
           \u8cc7\u6df1\u5927\u4f6c : zouzou0208 <\/span>  <\/div>\n
           <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                       \u53ea\u662f\u8fd8\u6ca1\u652f\u6301\u3002
          pep 622 \u4eca\u5e74\u521a\u51fa\u4e0d\u4e45\uff0c\u4f1a\u652f\u6301 match case \u3002\u867d\u7136\u906d\u5230\u4e86\u4e0d\u5c11\u53cd\u5bf9\u3002
          https:\/\/www.python.org\/dev\/peps\/pep-0622\/
          \u5f88\u53ef\u80fd 3.10 3.11 \u5c31\u770b\u5230\u4e86\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
        • \n
          \n
          \n
           \u8cc7\u6df1\u5927\u4f6c : renmu123 <\/span>  <\/div>\n
           <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                       \u6211\u6765\u603b\u7ed3\u4e00\u4e0b\uff1aGuido \u4e0d\u559c\u6b22 \"Python <\/div>\n<\/p><\/div>\n<\/li>\n
        • \n","protected":false},"excerpt":{"rendered":"
          Python \u4e3a\u4ec0\u4e48\u4e0d\u652f\u6301 swi…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/167255"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=167255"}],"version-history":[{"count":1,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/167255\/revisions"}],"predecessor-version":[{"id":167257,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/167255\/revisions\/167257"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=167255"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=167255"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=167255"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}