{"id":1172878,"date":"2025-01-15T16:55:46","date_gmt":"2025-01-15T08:55:46","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1172878.html"},"modified":"2025-01-15T16:55:48","modified_gmt":"2025-01-15T08:55:48","slug":"python%e5%ad%97%e5%85%b8%e5%a6%82%e4%bd%95%e6%8c%89%e7%85%a7%e9%94%ae%e5%80%bc%e6%9f%a5%e6%89%be","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1172878.html","title":{"rendered":"python\u5b57\u5178\u5982\u4f55\u6309\u7167\u952e\u503c\u67e5\u627e"},"content":{"rendered":"

\"python\u5b57\u5178\u5982\u4f55\u6309\u7167\u952e\u503c\u67e5\u627e\"<\/p>\n

Python\u5b57\u5178\u6309\u7167\u952e\u503c\u67e5\u627e\u7684\u65b9\u6cd5\u4e3b\u8981\u6709\uff1a\u4f7f\u7528\u5b57\u5178\u7684\u952e\u503c\u5bf9\u8fdb\u884c\u67e5\u627e\u3001\u4f7f\u7528\u5b57\u5178\u7684get\u65b9\u6cd5\u3001\u4f7f\u7528\u5b57\u5178\u7684items\u65b9\u6cd5\u904d\u5386\u3001\u4f7f\u7528\u5b57\u5178\u7684keys\u65b9\u6cd5\u904d\u5386\u3002<\/strong>\u4e0b\u9762\u8be6\u7ec6\u4ecb\u7ecd\u5176\u4e2d\u4e00\u79cd\u65b9\u6cd5\u2014\u2014\u4f7f\u7528\u5b57\u5178\u7684get\u65b9\u6cd5\u3002<\/p>\n<\/p>\n

\u4f7f\u7528\u5b57\u5178\u7684get\u65b9\u6cd5\u8fdb\u884c\u67e5\u627e\u662f\u4e00\u79cd\u975e\u5e38\u5e38\u89c1\u4e14\u5b89\u5168\u7684\u65b9\u6cd5\u3002\u5b57\u5178\u7684get\u65b9\u6cd5\u5141\u8bb8\u6211\u4eec\u901a\u8fc7\u63d0\u4f9b\u4e00\u4e2a\u952e\u6765\u67e5\u627e\u5bf9\u5e94\u7684\u503c\uff0c\u82e5\u952e\u4e0d\u5b58\u5728\uff0c\u8fd8\u53ef\u4ee5\u63d0\u4f9b\u4e00\u4e2a\u9ed8\u8ba4\u503c\u6765\u907f\u514d\u629b\u51fa\u5f02\u5e38\u3002\u5176\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n<\/p>\n

value = dictionary.get(key, default_value)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5176\u4e2d\uff0cdictionary<\/code>\u662f\u4f60\u8981\u67e5\u627e\u7684\u5b57\u5178\uff0ckey<\/code>\u662f\u4f60\u8981\u67e5\u627e\u7684\u952e\uff0cdefault_value<\/code>\u662f\u5f53\u952e\u4e0d\u5b58\u5728\u65f6\u8fd4\u56de\u7684\u9ed8\u8ba4\u503c\u3002\u793a\u4f8b\u5982\u4e0b\uff1a<\/p>\n<\/p>\n
my_dict = {'a': 1, 'b': 2, 'c': 3}<\/p>\n
value = my_dict.get('b', 'Not Found')<\/p>\n
print(value)  # \u8f93\u51fa: 2<\/p>\n
value = my_dict.get('d', 'Not Found')<\/p>\n
print(value)  # \u8f93\u51fa: Not Found<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\uff0c\u6211\u4eec\u80fd\u591f\u6709\u6548\u5730\u907f\u514d\u56e0\u952e\u4e0d\u5b58\u5728\u800c\u629b\u51faKeyError\u5f02\u5e38\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u5065\u58ee\u6027\u3002<\/p>\n<\/p>\n
\u4e00\u3001\u4f7f\u7528\u5b57\u5178\u7684\u952e\u503c\u5bf9\u8fdb\u884c\u67e5\u627e<\/h3>\n<\/p>\n
\u5728Python\u4e2d\uff0c\u5b57\u5178\u662f\u4e00\u79cd\u952e\u503c\u5bf9\u7684\u6570\u636e\u7ed3\u6784\u3002\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u76f4\u63a5\u4f7f\u7528\u952e\u6765\u8bbf\u95ee\u5bf9\u5e94\u7684\u503c\u3002\u8fd9\u79cd\u65b9\u6cd5\u975e\u5e38\u76f4\u89c2\u4e14\u9ad8\u6548\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
my_dict = {'a': 1, 'b': 2, 'c': 3}<\/p>\n
value = my_dict['b']<\/p>\n
print(value)  # \u8f93\u51fa: 2<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u7136\u800c\uff0c\u8fd9\u79cd\u65b9\u6cd5\u5728\u952e\u4e0d\u5b58\u5728\u65f6\u4f1a\u629b\u51faKeyError\u5f02\u5e38\uff0c\u56e0\u6b64\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\u9700\u8981\u7279\u522b\u6ce8\u610f\u3002<\/p>\n<\/p>\n
\u4e8c\u3001\u4f7f\u7528\u5b57\u5178\u7684get\u65b9\u6cd5<\/h3>\n<\/p>\n
\u5982\u524d\u6240\u8ff0\uff0c\u4f7f\u7528\u5b57\u5178\u7684get\u65b9\u6cd5\u662f\u4e00\u79cd\u5b89\u5168\u4e14\u5e38\u89c1\u7684\u67e5\u627e\u65b9\u5f0f\u3002\u4e0e\u76f4\u63a5\u4f7f\u7528\u952e\u503c\u5bf9\u67e5\u627e\u76f8\u6bd4\uff0cget\u65b9\u6cd5\u80fd\u591f\u6709\u6548\u907f\u514dKeyError\u5f02\u5e38\u7684\u53d1\u751f\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u5065\u58ee\u6027\u3002<\/p>\n<\/p>\n
\u4e09\u3001\u4f7f\u7528\u5b57\u5178\u7684items\u65b9\u6cd5\u904d\u5386<\/h3>\n<\/p>\n
\u5b57\u5178\u7684items\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u6240\u6709\u952e\u503c\u5bf9\u7684\u89c6\u56fe\u5bf9\u8c61\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u904d\u5386\u8fd9\u4e2a\u89c6\u56fe\u5bf9\u8c61\u6765\u67e5\u627e\u7279\u5b9a\u7684\u952e\u503c\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
my_dict = {'a': 1, 'b': 2, 'c': 3}<\/p>\n
for key, value in my_dict.items():<\/p>\n
    if key == 'b':<\/p>\n
        print(value)  # \u8f93\u51fa: 2<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5bf9\u5b57\u5178\u8fdb\u884c\u590d\u6742\u64cd\u4f5c\u7684\u573a\u666f\uff0c\u4f8b\u5982\u540c\u65f6\u67e5\u627e\u591a\u4e2a\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
\u56db\u3001\u4f7f\u7528\u5b57\u5178\u7684keys\u65b9\u6cd5\u904d\u5386<\/h3>\n<\/p>\n
\u5b57\u5178\u7684keys\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u6240\u6709\u952e\u7684\u89c6\u56fe\u5bf9\u8c61\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u904d\u5386\u8fd9\u4e2a\u89c6\u56fe\u5bf9\u8c61\u6765\u67e5\u627e\u7279\u5b9a\u7684\u952e\u503c\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
my_dict = {'a': 1, 'b': 2, 'c': 3}<\/p>\n
for key in my_dict.keys():<\/p>\n
    if key == 'b':<\/p>\n
        print(my_dict[key])  # \u8f93\u51fa: 2<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5bf9\u5b57\u5178\u7684\u952e\u8fdb\u884c\u7279\u5b9a\u64cd\u4f5c\u7684\u573a\u666f\uff0c\u4f8b\u5982\u68c0\u67e5\u67d0\u4e2a\u952e\u662f\u5426\u5b58\u5728\u3002<\/p>\n<\/p>\n
\u4e94\u3001\u603b\u7ed3<\/h3>\n<\/p>\n
Python\u5b57\u5178\u63d0\u4f9b\u4e86\u591a\u79cd\u67e5\u627e\u952e\u503c\u7684\u65b9\u6cd5\uff0c\u6bcf\u79cd\u65b9\u6cd5\u90fd\u6709\u5176\u9002\u7528\u7684\u573a\u666f\u3002\u76f4\u63a5\u4f7f\u7528\u952e\u503c\u5bf9\u67e5\u627e\u3001\u4f7f\u7528\u5b57\u5178\u7684get\u65b9\u6cd5\u3001\u4f7f\u7528\u5b57\u5178\u7684items\u65b9\u6cd5\u904d\u5386\u3001\u4f7f\u7528\u5b57\u5178\u7684keys\u65b9\u6cd5\u904d\u5386<\/strong>\u90fd\u662f\u5e38\u89c1\u4e14\u6709\u6548\u7684\u67e5\u627e\u65b9\u5f0f\u3002\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u9700\u6c42\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u6765\u63d0\u9ad8\u4ee3\u7801\u7684\u6548\u7387\u548c\u5065\u58ee\u6027\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
 \u5982\u4f55\u5728Python\u5b57\u5178\u4e2d\u9ad8\u6548\u5730\u67e5\u627e\u7279\u5b9a\u7684\u952e\uff1f<\/strong>
\u5728Python\u5b57\u5178\u4e2d\u67e5\u627e\u7279\u5b9a\u952e\u7684\u64cd\u4f5c\u975e\u5e38\u7b80\u5355\u3002\u53ef\u4ee5\u4f7f\u7528\u5b57\u5178\u7684in<\/code>\u5173\u952e\u5b57\u6765\u68c0\u67e5\u952e\u662f\u5426\u5b58\u5728\u3002\u4f8b\u5982\uff0cif key in my_dict:<\/code>\u53ef\u4ee5\u7528\u6765\u5224\u65adkey<\/code>\u662f\u5426\u5728\u5b57\u5178my_dict<\/code>\u4e2d\u3002\u5982\u679c\u5b58\u5728\uff0c\u53ef\u4ee5\u901a\u8fc7my_dict[key]<\/code>\u6765\u83b7\u53d6\u5bf9\u5e94\u7684\u503c\u3002<\/p>\n
\u5982\u679c\u6211\u60f3\u6309\u7167\u503c\u6765\u67e5\u627e\u5b57\u5178\u4e2d\u7684\u952e\uff0c\u8be5\u600e\u4e48\u505a\uff1f<\/strong>
\u5728Python\u5b57\u5178\u4e2d\uff0c\u901a\u5e38\u662f\u901a\u8fc7\u952e\u6765\u8bbf\u95ee\u503c\u3002\u5982\u679c\u9700\u8981\u901a\u8fc7\u503c\u67e5\u627e\u952e\uff0c\u53ef\u4ee5\u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f\u6216\u5faa\u73af\u904d\u5386\u5b57\u5178\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u4f7f\u7528[k for k, v in my_dict.items() if v == target_value]<\/code>\u6765\u83b7\u53d6\u6240\u6709\u5bf9\u5e94\u4e8etarget_value<\/code>\u7684\u952e\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u5408\u4e8e\u503c\u4e0d\u552f\u4e00\u7684\u60c5\u51b5\u3002<\/p>\n
\u5982\u4f55\u5904\u7406\u5b57\u5178\u4e2d\u952e\u7684\u67e5\u627e\u5931\u8d25\u7684\u60c5\u51b5\uff1f<\/strong>
\u5728\u67e5\u627e\u5b57\u5178\u4e2d\u7684\u952e\u65f6\uff0c\u5982\u679c\u8be5\u952e\u4e0d\u5b58\u5728\uff0c\u53ef\u4ee5\u4f7f\u7528dict.get(key, default_value)<\/code>\u65b9\u6cd5\u6765\u907f\u514d\u629b\u51fa\u5f02\u5e38\u3002\u5f53\u952e\u4e0d\u5b58\u5728\u65f6\uff0cget<\/code>\u65b9\u6cd5\u4f1a\u8fd4\u56dedefault_value<\/code>\uff0c\u800c\u4e0d\u662f\u5f15\u53d1KeyError<\/code>\u3002\u8fd9\u4f7f\u5f97\u5728\u67e5\u627e\u65f6\u66f4\u52a0\u5b89\u5168\u548c\u7075\u6d3b\uff0c\u9002\u7528\u4e8e\u9700\u8981\u63d0\u4f9b\u9ed8\u8ba4\u503c\u7684\u573a\u666f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"Python\u5b57\u5178\u6309\u7167\u952e\u503c\u67e5\u627e\u7684\u65b9\u6cd5\u4e3b\u8981\u6709\uff1a\u4f7f\u7528\u5b57\u5178\u7684\u952e\u503c\u5bf9\u8fdb\u884c\u67e5\u627e\u3001\u4f7f\u7528\u5b57\u5178\u7684get\u65b9\u6cd5\u3001\u4f7f\u7528\u5b57\u5178\u7684items […]","protected":false},"author":3,"featured_media":1172879,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1172878"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=1172878"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1172878\/revisions"}],"predecessor-version":[{"id":1172880,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1172878\/revisions\/1172880"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/1172879"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=1172878"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=1172878"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=1172878"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}