<\/p>\n
\u5728 Python \u4e2d\uff0c`__setitem__` \u662f\u4e00\u500b\u7279\u6b8a\u65b9\u6cd5\uff0c\u5141\u8a31\u4f60\u5728\u985e\u5225\u4e2d\u8a2d\u5b9a\u5c6c\u6027\uff0c\u800c\u4e0d\u9700\u8981\u4f7f\u7528\u7279\u5b9a\u7684\u8a2d\u5b9a\u51fd\u5f0f\u3002\u4f7f\u7528 `__setitem__` \u65b9\u6cd5\u53ef\u4ee5\u8b93\u4f60\u66f4\u9748\u6d3b\u5730\u63a7\u5236\u5c6c\u6027\u7684\u8a2d\u5b9a\uff0c\u4e26\u4e14\u4f7f\u4ee3\u78bc\u66f4\u52a0\u6613\u8b80\u8207\u53ef\u7dad\u8b77\u3002<\/p>\n
### `__setitem__` \u65b9\u6cd5\u7684\u57fa\u672c\u7528\u6cd5<\/p>\n
`__setitem__` \u65b9\u6cd5\u7684\u4f7f\u7528\u65b9\u5f0f\u975e\u5e38\u7c21\u55ae\u3002\u5b83\u63a5\u53d7\u5169\u500b\u53c3\u6578\uff1a\u7b2c\u4e00\u500b\u53c3\u6578\u662f\u8981\u8a2d\u5b9a\u7684\u5c6c\u6027\u540d\u7a31\uff08\u901a\u5e38\u662f\u9375\uff09\uff0c\u7b2c\u4e8c\u500b\u53c3\u6578\u662f\u8981\u8a2d\u5b9a\u7684\u5c6c\u6027\u503c\u3002\u4f8b\u5982\uff0c\u82e5\u4f60\u60f3\u8981\u5728\u985e\u5225\u4e2d\u8a2d\u5b9a\u4e00\u500b\u540d\u70ba `name` \u7684\u5c6c\u6027\uff0c\u4e26\u5c07\u5176\u503c\u8a2d\u5b9a\u70ba “John”\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u7684\u7a0b\u5f0f\u78bc\uff1a<\/p>\n
“`python
\nclass MyClass:
\n def __init__(self):
\n self.data = {}<\/p>\n
def __setitem__(self, key, value):
\n self.data[key] = value<\/p>\n
my_class = MyClass()
\nmy_class[‘name’] = ‘John’
\n“`<\/p>\n
\u5728\u4e0a\u8ff0\u7a0b\u5f0f\u78bc\u4e2d\uff0c\u6211\u5011\u81ea\u5b9a\u7fa9\u4e86 `__setitem__` \u65b9\u6cd5\uff0c\u4ee5\u4fbf\u5728 `MyClass` \u7269\u4ef6\u4e2d\u4f7f\u7528 `[]` \u8a2d\u5b9a\u5c6c\u6027\u3002\u9019\u6a23\u4e00\u4f86\uff0c\u7576\u6211\u5011\u4f7f\u7528 `my_class[‘name’] = ‘John’` \u6642\uff0c\u5be6\u969b\u4e0a\u662f\u547c\u53eb\u4e86 `__setitem__` \u65b9\u6cd5\u3002<\/p>\n
### \u8a2d\u5b9a\u5176\u4ed6\u5c6c\u6027<\/p>\n
\u9664\u4e86 `name` \u5c6c\u6027\u5916\uff0c\u6211\u5011\u9084\u53ef\u4ee5\u4f7f\u7528 `__setitem__` \u8a2d\u5b9a\u5176\u4ed6\u5c6c\u6027\uff0c\u4f8b\u5982 `age` \u548c `is_active`\uff1a<\/p>\n
“`python
\nmy_class[‘age’] = 20
\nmy_class[‘is_active’] = True
\n“`<\/p>\n
\u9019\u4e9b\u64cd\u4f5c\u5c07\u81ea\u52d5\u547c\u53eb `__setitem__` \u65b9\u6cd5\uff0c\u4e26\u5c07\u5c0d\u61c9\u7684\u9375\u503c\u5c0d\u5b58\u5165 `data` \u5b57\u5178\u4e2d\u3002<\/p>\n
### \u932f\u8aa4\u6392\u9664<\/p>\n
\u7576\u4f7f\u7528 `__setitem__` \u65b9\u6cd5\u6642\uff0c\u4f60\u53ef\u80fd\u6703\u9047\u5230\u4e00\u4e9b\u5e38\u898b\u7684\u932f\u8aa4\uff0c\u4f8b\u5982\uff1a<\/p>\n
– **KeyError**\uff1a\u5982\u679c\u4f60\u8a66\u5716\u8a2a\u554f\u4e00\u500b\u4e0d\u5b58\u5728\u7684\u9375\uff0c\u5c07\u6703\u5f15\u767c\u6b64\u932f\u8aa4\u3002\u5728\u5be6\u4f5c\u4e2d\uff0c\u4f60\u53ef\u4ee5\u8003\u616e\u5728 `__getitem__` \u65b9\u6cd5\u4e2d\u52a0\u5165\u932f\u8aa4\u8655\u7406\u6a5f\u5236\u3002
\n– **TypeError**\uff1a\u78ba\u4fdd\u4f60\u50b3\u905e\u7d66 `__setitem__` \u7684\u9375\u662f\u53ef\u54c8\u5e0c\u7684\u985e\u578b\uff08\u5982\u5b57\u7b26\u4e32\u6216\u6578\u5b57\uff09\u3002<\/p>\n
### \u5ef6\u4f38\u61c9\u7528<\/p>\n
`__setitem__` \u65b9\u6cd5\u53ef\u4ee5\u88ab\u7528\u65bc\u5404\u7a2e\u61c9\u7528\u5834\u666f\uff0c\u4f8b\u5982\uff1a<\/p>\n
– **\u81ea\u5b9a\u7fa9\u8cc7\u6599\u7d50\u69cb**\uff1a\u4f60\u53ef\u4ee5\u5229\u7528 `__setitem__` \u65b9\u6cd5\u4f86\u5275\u5efa\u5177\u6709\u7279\u5b9a\u884c\u70ba\u7684\u81ea\u5b9a\u7fa9\u8cc7\u6599\u7d50\u69cb\u3002
\n– **\u6578\u64da\u9a57\u8b49**\uff1a\u5728\u8a2d\u7f6e\u5c6c\u6027\u6642\uff0c\u4f60\u53ef\u4ee5\u52a0\u5165\u6578\u64da\u9a57\u8b49\u908f\u8f2f\uff0c\u78ba\u4fdd\u50b3\u5165\u7684\u503c\u7b26\u5408\u7279\u5b9a\u689d\u4ef6\u3002<\/p>\n
\u4f8b\u5982\uff0c\u82e5\u5e0c\u671b\u5728\u8a2d\u5b9a\u5e74\u9f61\u6642\u9032\u884c\u6aa2\u67e5\uff0c\u53ef\u4ee5\u9019\u6a23\u5be6\u4f5c\uff1a<\/p>\n
“`python
\nclass MyClass:
\n def __init__(self):
\n self.data = {}<\/p>\n
def __setitem__(self, key, value):
\n if key == ‘age’ and value < 0:\n raise ValueError(\"\u5e74\u9f61\u4e0d\u80fd\u70ba\u8ca0\u6578\")\n self.data[key] = value\n```\n\n\u9019\u6a23\u5c31\u80fd\u78ba\u4fdd\u4e0d\u6703\u5c07\u8ca0\u6578\u5e74\u9f61\u5b58\u5165\u7269\u4ef6\u4e2d\u3002\n\n### \u7d50\u8ad6\n\n\u4f7f\u7528 `__setitem__` \u65b9\u6cd5\u4e0d\u50c5\u80fd\u5920\u7c21\u5316\u5c6c\u6027\u8a2d\u5b9a\u7684\u904e\u7a0b\uff0c\u4e5f\u80fd\u589e\u5f37\u4ee3\u78bc\u7684\u53ef\u8b80\u6027\u548c\u53ef\u7dad\u8b77\u6027\u3002\u900f\u904e\u9019\u7a2e\u65b9\u5f0f\uff0c\u4f60\u53ef\u4ee5\u9748\u6d3b\u5730\u7ba1\u7406\u7269\u4ef6\u7684\u5c6c\u6027\uff0c\u4e26\u5be6\u73fe\u66f4\u8907\u96dc\u7684\u884c\u70ba\u3002\n\n\u5982\u9700\u66f4\u6df1\u5165\u7684 Python \u6559\u5b78\uff0c\u5efa\u8b70\u53c3\u8003 [vocus.cc \u7684 Python \u6559\u5b78\u6587\u7ae0](https:\/\/vocus.cc) \u6216 [miner.tw \u7684\u76f8\u95dc\u8cc7\u6e90](https:\/\/miner.tw)\u3002\n\n### Q&A\uff08\u5e38\u898b\u554f\u984c\u89e3\u7b54\uff09\n\n**Q1: `__setitem__` \u548c\u666e\u901a\u7684\u5c6c\u6027\u8a2d\u5b9a\u6709\u4ec0\u9ebc\u4e0d\u540c\uff1f** \nA: `__setitem__` \u5141\u8a31\u4f7f\u7528 `[]` \u8a9e\u6cd5\u4f86\u8a2d\u5b9a\u5c6c\u6027\uff0c\u9019\u6a23\u53ef\u4ee5\u8b93\u4ee3\u78bc\u66f4\u5177\u53ef\u8b80\u6027\uff0c\u4e26\u4e14\u80fd\u5920\u5728\u8a2d\u5b9a\u904e\u7a0b\u4e2d\u52a0\u5165\u81ea\u5b9a\u7fa9\u7684\u908f\u8f2f\u3002\n\n**Q2: \u6211\u53ef\u4ee5\u5728 `__setitem__` \u4e2d\u9032\u884c\u54ea\u4e9b\u64cd\u4f5c\uff1f** \nA: \u4f60\u53ef\u4ee5\u5728 `__setitem__` \u4e2d\u9032\u884c\u6578\u64da\u9a57\u8b49\u3001\u8f49\u63db\u8f38\u5165\u503c\u3001\u8a18\u9304\u8a2d\u5b9a\u7684\u8b8a\u66f4\u7b49\u3002\n\n**Q3: \u5982\u4f55\u8655\u7406\u4f7f\u7528 `__setitem__` \u6642\u53ef\u80fd\u51fa\u73fe\u7684\u932f\u8aa4\uff1f** \nA: \u4f60\u53ef\u4ee5\u5728 `__setitem__` \u4e2d\u52a0\u5165\u932f\u8aa4\u8655\u7406\u6a5f\u5236\uff0c\u4f8b\u5982\u4f7f\u7528 `try...except` \u8a9e\u53e5\u4f86\u6355\u7372\u4e26\u8655\u7406\u7570\u5e38\u3002\n\n---\n<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e86\u89e3Python\u4e2d\u7684class_setitem()\u65b9\u6cd5\uff0c\u5b83\u53ef\u4ee5\u8b93\u4f60\u8a2d\u7f6e\u7269\u4ef6\u7684\u5c6c\u6027\uff0c\u4e26\u63d0\u4f9b\u4e00\u500b\u7c21\u55ae\u7684\u65b9\u6cd5\u4f86\u8a2d\u7f6e\u7269\u4ef6\u7684\u5c6c\u6027\uff0c\u4ee5\u6eff\u8db3GoogleSEO\u539f\u5247\u3002<\/p>\n","protected":false},"author":1,"featured_media":2518,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[18],"tags":[15],"class_list":["post-3344","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-python","tag-python"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/badgameshow.com\/steven\/wp-content\/uploads\/2022\/12\/DALL\u00b7E-2022-12-28-14.25.55-\u62f7\u8c9d2.png","jetpack-related-posts":[],"jetpack_shortlink":"https:\/\/wp.me\/pcFK27-RW","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/3344","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/comments?post=3344"}],"version-history":[{"count":1,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/3344\/revisions"}],"predecessor-version":[{"id":3345,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/3344\/revisions\/3345"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/media\/2518"}],"wp:attachment":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/media?parent=3344"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/categories?post=3344"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/tags?post=3344"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}