{"id":106634,"date":"2026-09-17T20:16:37","date_gmt":"2026-09-17T12:16:37","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/106634.html"},"modified":"2026-09-17T20:16:37","modified_gmt":"2026-09-17T12:16:37","slug":"07-%e6%9d%a1%e4%bb%b6%e5%88%a4%e6%96%ad%ef%bc%9a%e8%ae%a9%e7%a8%8b%e5%ba%8f%e5%ad%a6%e4%bc%9a%e9%80%89%e6%8b%a9%ef%bc%88if-%c2%b7-elif-%c2%b7-else-%c2%b7-%e9%80%bb%e8%be%91%e8%bf%90%e7%ae%97%e7%ac%a6","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/106634.html","title":{"rendered":"07 \u6761\u4ef6\u5224\u65ad\uff1a\u8ba9\u7a0b\u5e8f\u5b66\u4f1a\u9009\u62e9\uff08if \u00b7 elif \u00b7 else \u00b7 \u903b\u8f91\u8fd0\u7b97\u7b26\uff09"},"content":{"rendered":"

\u4e0a\u4e00\u7bc7：06 \u5b57\u5178：\u952e\u503c\u5bf9\u7ec4\u7ec7\u6570\u636e（\u589e\u5220\u6539\u67e5 \u00b7 \u5d4c\u5957 \u00b7 JSON \u6570\u636e\u601d\u7ef4）<\/p>\n

\n

\u4e0a\u7bc7\u7ec3\u4e60\u53c2\u8003\u7b54\u6848<\/h3>\n

\u7ec3\u4e60 1（\u4e24\u5c42\u8bbf\u95ee）：\u5bf9\u4e0b\u9762\u8fd9\u4e2a\u5b57\u5178，\u5404\u7528\u4e00\u884c\u4ee3\u7801\u53d6\u51fa"\u674e\u56db\u7684\u624b\u673a"\u548c"\u8d75\u516d\u7684\u57ce\u5e02"，\u5e76\u5199\u51fa\u628a\u8d75\u516d\u57ce\u5e02\u6539\u6210"\u6df1\u5733"\u7684\u4e00\u884c：<\/p>\n

contacts =<\/span> {<\/span>
\n "\u5f20\u4e09"<\/span>:<\/span> {<\/span>"phone"<\/span>:<\/span> "138****5678"<\/span>,<\/span> "city"<\/span>:<\/span> "\u5317\u4eac"<\/span>}<\/span>,<\/span>
\n "\u674e\u56db"<\/span>:<\/span> {<\/span>"phone"<\/span>:<\/span> "139****1234"<\/span>,<\/span> "city"<\/span>:<\/span> "\u4e0a\u6d77"<\/span>}<\/span>,<\/span>
\n "\u8d75\u516d"<\/span>:<\/span> {<\/span>"phone"<\/span>:<\/span> "137****9012"<\/span>,<\/span> "city"<\/span>:<\/span> "\u676d\u5dde"<\/span>}<\/span>,<\/span>
\n}<\/span><\/p>\n

print<\/span>(<\/span>contacts[<\/span>"\u674e\u56db"<\/span>]<\/span>[<\/span>"phone"<\/span>]<\/span>)<\/span> # 139****1234<\/span>
\nprint<\/span>(<\/span>contacts[<\/span>"\u8d75\u516d"<\/span>]<\/span>[<\/span>"city"<\/span>]<\/span>)<\/span> # \u676d\u5dde<\/span>
\ncontacts[<\/span>"\u8d75\u516d"<\/span>]<\/span>[<\/span>"city"<\/span>]<\/span> =<\/span> "\u6df1\u5733"<\/span> # \u4e24\u5c42\u5b9a\u4f4d，\u76f4\u63a5\u8d4b\u503c<\/span><\/p>\n

\u7ec3\u4e60 2（\u9884\u6d4b\u518d\u9a8c\u8bc1）：len({"a": 1, "b": 2})\u3001{"a": 1}["a"]\u3001{"a": 1}.get("b", 0)\u3001"a" in {"a": 1} \u5404\u662f\u4ec0\u4e48？\u5199\u4e0b\u7b54\u6848，\u8fdb\u4ea4\u4e92\u6a21\u5f0f\u9a8c\u8bc1，\u9519\u7684\u8d34\u8bc4\u8bba\u533a； \"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"<\/p>\n

len({"a": 1, "b": 2}) \u2192 2（\u6570\u5bf9\u6570）； {"a": 1}["a"] \u2192 1； {"a": 1}.get("b", 0) \u2192 0（\u515c\u5e95\u503c）； "a" in {"a": 1} \u2192 True（in \u67e5\u7684\u662f\u952e）\u3002<\/p>\n

\u7ec3\u4e60 3（\u8bfe\u7a0b\u6210\u7ee9\u5355）：\u5efa\u5b57\u5178 scores = {"Python": 92, "Excel": 85, "\u6c47\u62a5": 78}，\u7528 .values() \u6253\u5370：\u95e8\u6570\u3001\u603b\u5206\u3001\u5e73\u5747\u5206（\u4e00\u4f4d\u5c0f\u6570）\u3001\u6700\u9ad8\u5206；\u518d\u7528 3.4 \u8282\u7684\u4e24\u884c\u904d\u5386\u6a21\u677f，\u9010\u884c\u6253\u5370\u6bcf\u95e8\u8bfe<\/p>\n

scores =<\/span> {<\/span>"Python"<\/span>:<\/span> 92<\/span>,<\/span> "Excel"<\/span>:<\/span> 85<\/span>,<\/span> "\u6c47\u62a5"<\/span>:<\/span> 78<\/span>}<\/span>
\nprint<\/span>(<\/span>scores.<\/span>values(<\/span>)<\/span>)<\/span> # \u628a\u6240\u6709\u503c\u53d6\u51fa\u4e3a\u5217\u8868<\/span>
\nprint<\/span>(<\/span>len<\/span>(<\/span>scores.<\/span>values(<\/span>)<\/span>)<\/span>)<\/span> # \u95e8\u6570<\/span>
\nprint<\/span>(<\/span>sum<\/span>(<\/span>scores.<\/span>values(<\/span>)<\/span>)<\/span>)<\/span> # \u603b\u5206<\/span>
\nprint<\/span>(<\/span>max<\/span>(<\/span>scores.<\/span>values(<\/span>)<\/span>)<\/span>)<\/span> # \u6700\u9ad8\u5206<\/span>
\nprint<\/span>(<\/span>f"<\/span>{<\/span>sum<\/span>(<\/span>scores.<\/span>values(<\/span>)<\/span>)<\/span> \/<\/span> len<\/span>(<\/span>scores)<\/span>:<\/span>.1f<\/span>}<\/span><\/span>"<\/span><\/span>)<\/span> # \u5e73\u5747\u5206（\u4e00\u4f4d\u5c0f\u6570）<\/span><\/p>\n

# \u9010\u884c\u6253\u5370\u6bcf\u95e8\u8bfe<\/span>
\nprint<\/span>(<\/span>"\\\\n=========== \u9010\u884c\u6253\u5370\u6bcf\u95e8\u8bfe ==========="<\/span>)<\/span>
\nfor<\/span> subject,<\/span> score in<\/span> scores.<\/span>items(<\/span>)<\/span>:<\/span>
\n print<\/span>(<\/span>f"<\/span>{<\/span>subject}<\/span><\/span>：<\/span>{<\/span>score}<\/span><\/span> "<\/span><\/span>)<\/span><\/p>\n

\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" 3 \u95e8\u3001\u603b\u5206 255\u3001\u5e73\u5747 85.0\u3001\u6700\u9ad8 92；<\/p>\n

\u7ec3\u4e60 4（\u75ab\u82d7\u63ed\u6653）：\u6267\u884c print(budget[\u201c\u6280\u672f\u90e8\u201d] > 30000)（budget \u7528\u672c\u7bc7\u6570\u636e），\u770b\u8f93\u51fa\u662f\u54ea\u4e2a\u8001\u670b\u53cb\u2014\u2014\u4e0b\u4e00\u7bc7，\u7a0b\u5e8f\u8981\u5f00\u59cb\u81ea\u5df1\u62ff\u4e3b\u610f\u4e86\u3002 \"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" budget["\u6280\u672f\u90e8"] > 30000 \u2192 True\u3002 03 \u7bc7\u7684\u5e03\u5c14\u503c\u8001\u670b\u53cb\u2014\u2014\u6bd4\u8f83\u7684\u7ed3\u679c\u662f\u5e03\u5c14\u503c，\u800c"\u6839\u636e\u5e03\u5c14\u503c\u8d70\u4e0d\u540c\u8def"，\u5c31\u662f\u672c\u7bc7\u7684\u5168\u90e8\u5185\u5bb9\u3002<\/p>\n

\n

\u4e00\u3001\u573a\u666f\u5f15\u5165：\u8ba9\u7a0b\u5e8f\u7b2c\u4e00\u6b21"\u62ff\u4e3b\u610f"<\/h3>\n

\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \u524d\u516d\u7bc7\u7684\u7a0b\u5e8f\u90fd\u662f"\u4e00\u6761\u9053\u8d70\u5230\u9ed1"：\u4ece\u7b2c\u4e00\u884c\u6267\u884c\u5230\u6700\u540e\u4e00\u884c，\u4e00\u884c\u4e0d\u843d\u3002\u4f46\u771f\u5b9e\u7684\u5de5\u4f5c\u6d41\u7a0b\u5145\u6ee1\u5c94\u8def：<\/p>\n