{"id":4331,"date":"2022-03-19T22:58:36","date_gmt":"2022-03-19T14:58:36","guid":{"rendered":"https:\/\/egonlin.com\/?p=4331"},"modified":"2022-04-11T19:04:58","modified_gmt":"2022-04-11T11:04:58","slug":"%e7%ac%ac%e4%b9%9d%e8%8a%82%ef%bc%9a%e5%bc%82%e5%b8%b8%e5%a4%84%e7%90%86","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=4331","title":{"rendered":"\u7b2c\u4e5d\u8282\uff1a\u5f02\u5e38\u5904\u7406"},"content":{"rendered":"<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u5f02\u5e38\u5904\u74061.jpg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u5f02\u5e38\u5904\u74061.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<h1>\u4e00 \u4ec0\u4e48\u662f\u5f02\u5e38<\/h1>\n<p>\u5f02\u5e38\u662f\u7a0b\u5e8f\u53d1\u751f\u9519\u8bef\u7684\u4fe1\u53f7\u3002\u7a0b\u5e8f\u4e00\u65e6\u51fa\u73b0\u9519\u8bef\uff0c\u4fbf\u4f1a\u4ea7\u751f\u4e00\u4e2a\u5f02\u5e38\uff0c\u82e5\u7a0b\u5e8f\u4e2d\u6ca1\u6709\u5904\u7406\u5b83\uff0c\u5c31\u4f1a\u629b\u51fa\u8be5\u5f02\u5e38\uff0c\u7a0b\u5e8f\u7684\u8fd0\u884c\u4e5f\u968f\u4e4b\u7ec8\u6b62\u3002\u5728Python\u4e2d,\u9519\u8bef\u89e6\u53d1\u7684\u5f02\u5e38\u5982\u4e0b<\/p>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u5f02\u5e38\u5904\u7406.jpg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u5f02\u5e38\u5904\u7406.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>\u800c\u9519\u8bef\u5206\u6210\u4e24\u79cd\uff0c\u4e00\u79cd\u662f\u8bed\u6cd5\u4e0a\u7684\u9519\u8befSyntaxError\uff0c\u8fd9\u79cd\u9519\u8bef\u5e94\u8be5\u5728\u7a0b\u5e8f\u8fd0\u884c\u524d\u5c31\u4fee\u6539\u6b63\u786e<\/p>\n<pre><code class=\"language-python\">>&gt;&gt; if  \n  File &quot;&lt;stdin&gt;&quot;, line 1\n    if\n     ^\nSyntaxError: invalid syntax<\/code><\/pre>\n<p>\u53e6\u4e00\u7c7b\u5c31\u662f\u903b\u8f91\u9519\u8bef\uff0c\u5e38\u89c1\u7684\u903b\u8f91\u9519\u8bef\u5982<\/p>\n<pre><code class=\"language-python\"># TypeError\uff1a\u6570\u5b57\u7c7b\u578b\u65e0\u6cd5\u4e0e\u5b57\u7b26\u4e32\u7c7b\u578b\u76f8\u52a0\n1+\u20192\u2019\n\n# ValueError\uff1a\u5f53\u5b57\u7b26\u4e32\u5305\u542b\u6709\u975e\u6570\u5b57\u7684\u503c\u65f6\uff0c\u65e0\u6cd5\u8f6c\u6210int\u7c7b\u578b\nnum=input(&quot;&gt;&gt;: &quot;) #\u8f93\u5165hello\nint(num)\n\n# NameError\uff1a\u5f15\u7528\u4e86\u4e00\u4e2a\u4e0d\u5b58\u5728\u7684\u540d\u5b57x\nx\n\n# IndexError\uff1a\u7d22\u5f15\u8d85\u51fa\u5217\u8868\u7684\u9650\u5236\nl=[&#039;egon&#039;,&#039;aa&#039;]\nl[3]\n\n# KeyError\uff1a\u5f15\u7528\u4e86\u4e00\u4e2a\u4e0d\u5b58\u5728\u7684key\ndic={&#039;name&#039;:&#039;egon&#039;}\ndic[&#039;age&#039;]\n\n# AttributeError\uff1a\u5f15\u7528\u7684\u5c5e\u6027\u4e0d\u5b58\u5728\nclass Foo:\n    pass\nFoo.x\n\n# ZeroDivisionError\uff1a\u9664\u6570\u4e0d\u80fd\u4e3a0\n1\/0<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe01-3.jpeg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe01-3.jpeg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<h1>\u4e8c \u5f02\u5e38\u5904\u7406<\/h1>\n<p>\u4e3a\u4e86\u4fdd\u8bc1\u7a0b\u5e8f\u7684\u5bb9\u9519\u6027\u4e0e\u53ef\u9760\u6027\uff0c\u5373\u5728\u9047\u5230\u9519\u8bef\u65f6\u6709\u76f8\u5e94\u7684\u5904\u7406\u673a\u5236\u4e0d\u4f1a\u4efb\u7531\u7a0b\u5e8f\u5d29\u6e83\u6389\uff0c\u6211\u4eec\u9700\u8981\u5bf9\u5f02\u5e38\u8fdb\u884c\u5904\u7406\uff0c\u5904\u7406\u7684\u57fa\u672c\u5f62\u5f0f\u4e3a<\/p>\n<pre><code class=\"language-python\">try:\n    \u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\nexcept \u5f02\u5e38\u7c7b\u578b\uff1a\n    \u68c0\u6d4b\u5230\u5f02\u5e38\uff0c\u5c31\u6267\u884c\u8fd9\u4e2a\u4f4d\u7f6e\u7684\u903b\u8f91<\/code><\/pre>\n<p>\u4e3e\u4f8b<\/p>\n<pre><code class=\"language-python\">try:\n    print(&#039;start...&#039;)\n    print(x) # \u5f15\u7528\u4e86\u4e00\u4e2a\u4e0d\u5b58\u5728\u7684\u540d\u5b57\uff0c\u89e6\u53d1\u5f02\u5e38NameError\n    print(&#039;end...&#039;)\nexcept NameError as e: # as\u8bed\u6cd5\u5c06\u5f02\u5e38\u7c7b\u578b\u7684\u503c\u8d4b\u503c\u7ed9\u53d8\u91cfe\uff0c\u8fd9\u6837\u6211\u4eec\u901a\u8fc7\u6253\u5370e\u4fbf\u53ef\u4ee5\u77e5\u9053\u9519\u8bef\u7684\u539f\u56e0\n    print(&#039;\u5f02\u5e38\u503c\u4e3a\uff1a%s&#039; %e)\nprint(&#039;run other code...&#039;)\n\n#\u6267\u884c\u7ed3\u679c\u4e3a\nstart...\n\u5f02\u5e38\u503c\u4e3a\uff1aname &#039;x&#039; is not defined\nrun other code...<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe02-5.jpeg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe02-5.jpeg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>\u672c\u6765\u7a0b\u5e8f\u4e00\u65e6\u51fa\u73b0\u5f02\u5e38\u5c31\u6574\u4f53\u7ed3\u675f\u6389\u4e86\uff0c\u6709\u4e86\u5f02\u5e38\u5904\u7406\u4ee5\u540e\uff0c\u5728\u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\u51fa\u73b0\u5f02\u5e38\u65f6\uff0c\u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\u4e2d\u5f02\u5e38\u53d1\u751f\u4f4d\u7f6e\u4e4b\u540e\u7684\u4ee3\u7801\u5c06\u4e0d\u4f1a\u6267\u884c\uff0c\u53d6\u800c\u4ee3\u4e4b\u7684\u662f\u6267\u884c\u5339\u914d\u5f02\u5e38\u7684except\u5b50\u4ee3\u7801\u5757\uff0c\u5176\u4f59\u4ee3\u7801\u5747\u6b63\u5e38\u8fd0\u884c\u3002<\/p>\n<p>\u200b   \u5f53\u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\u4e2d\u6709\u53ef\u80fd\u89e6\u53d1\u4e0d\u540c\u7c7b\u578b\u7684\u5f02\u5e38\u65f6\uff0c\u9488\u5bf9\u4e0d\u540c\u7c7b\u578b\u7684\u5f02\u5e38\uff1a<\/p>\n<p>\u200b   \u5982\u679c\u6211\u4eec\u60f3\u5206\u522b\u7528\u4e0d\u540c\u7684\u903b\u8f91\u5904\u7406\uff0c\u9700\u8981\u7528\u5230\u591a\u5206\u652f\u7684except\uff08\u7c7b\u4f3c\u4e8e\u591a\u5206\u652f\u7684elif\uff0c\u4ece\u4e0a\u5230\u4e0b\u4f9d\u6b21\u5339\u914d\uff0c\u5339\u914d\u6210\u529f\u4e00\u6b21\u4fbf\u4e0d\u518d\u5339\u914d\u5176\u4ed6\uff09<\/p>\n<pre><code class=\"language-python\">try:\n    \u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\nexcept NameError:\n    \u89e6\u53d1NameError\u65f6\u5bf9\u5e94\u7684\u5904\u7406\u903b\u8f91\nexcept IndexError:\n    \u89e6\u53d1IndexError\u65f6\u5bf9\u5e94\u7684\u5904\u7406\u903b\u8f91\nexcept KeyError:\n    \u89e6\u53d1KeyError\u65f6\u5bf9\u5e94\u7684\u5904\u7406\u903b\u8f91<\/code><\/pre>\n<p>\u4e3e\u4f8b<\/p>\n<pre><code class=\"language-python\">def convert_int(obj):\n    try:\n        res=int(obj)\n    except ValueError as e:\n        print(&#039;ValueError: %s&#039; %e)\n        res=None\n    except TypeError as e:\n        print(&#039;TypeError: %s&#039; %e)\n        res=None\n    return res\n\nconvert_int(&#039;egon&#039;) # ValueError: invalid literal for int() with base 10: &#039;egon&#039;\nconvert_int({&#039;n&#039;:1}) # TypeError: int() argument must be a string, a bytes-like object or a number, not &#039;dict&#039;<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe03-3.jpeg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe03-3.jpeg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>\u5982\u679c\u6211\u4eec\u60f3\u591a\u79cd\u7c7b\u578b\u7684\u5f02\u5e38\u7edf\u4e00\u7528\u4e00\u79cd\u903b\u8f91\u5904\u7406\uff0c\u53ef\u4ee5\u5c06\u591a\u4e2a\u5f02\u5e38\u653e\u5230\u4e00\u4e2a\u5143\u7ec4\u5185\uff0c\u7528\u4e00\u4e2aexcept\u5339\u914d<\/p>\n<pre><code class=\"language-python\">try:\n    \u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\nexcept (NameError,IndexError,TypeError):\n    \u89e6\u53d1NameError\u6216IndexError\u6216TypeError\u65f6\u5bf9\u5e94\u7684\u5904\u7406\u903b\u8f91<\/code><\/pre>\n<p>\u4e3e\u4f8b<\/p>\n<pre><code class=\"language-python\">def convert_int(obj):\n    try:\n        res=int(obj)\n    except (ValueError,TypeError):\n        print(&#039;argument must be number or numeric string&#039;)\n        res=None\n    return res\n\nconvert_int(&#039;egon&#039;) # argument must be number or numeric string\nconvert_int({&#039;n&#039;:1}) # argument must be number or numeric string<\/code><\/pre>\n<p>\u5982\u679c\u6211\u4eec\u60f3\u6355\u83b7\u6240\u6709\u5f02\u5e38\u5e76\u7528\u4e00\u79cd\u903b\u8f91\u5904\u7406\uff0cPython\u63d0\u4f9b\u4e86\u4e00\u4e2a\u4e07\u80fd\u5f02\u5e38\u7c7b\u578bException<\/p>\n<pre><code class=\"language-python\">try:\n    \u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\nexcept NameError:\n    \u89e6\u53d1NameError\u65f6\u5bf9\u5e94\u7684\u5904\u7406\u903b\u8f91\nexcept IndexError:\n    \u89e6\u53d1IndexError\u65f6\u5bf9\u5e94\u7684\u5904\u7406\u903b\u8f91\nexcept Exception:\n    \u5176\u4ed6\u7c7b\u578b\u7684\u5f02\u5e38\u7edf\u4e00\u7528\u6b64\u5904\u7684\u903b\u8f91\u5904\u7406<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe08-3.jpeg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe08-3.jpeg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>\u5728\u591a\u5206\u652fexcept\u4e4b\u540e\u8fd8\u53ef\u4ee5\u8ddf\u4e00\u4e2aelse\uff08else\u5fc5\u987b\u8ddf\u5728except\u4e4b\u540e\uff0c\u4e0d\u80fd\u5355\u72ec\u5b58\u5728\uff09\uff0c\u53ea\u6709\u5728\u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\u6ca1\u6709\u89e6\u53d1\u4efb\u4f55\u5f02\u5e38\u7684\u60c5\u51b5\u4e0b\u624d\u4f1a\u6267\u884celse\u7684\u5b50\u4ee3\u7801\u5757<\/p>\n<pre><code class=\"language-python\">try:\n    \u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\nexcept \u5f02\u5e38\u7c7b\u578b1:\n    pass\nexcept \u5f02\u5e38\u7c7b\u578b2:\n    pass\n......\nelse:\n    \u6ca1\u6709\u5f02\u5e38\u53d1\u751f\u65f6\u6267\u884c\u7684\u4ee3\u7801\u5757<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe04-4.jpeg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe04-4.jpeg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>\u6b64\u5916try\u8fd8\u53ef\u4ee5\u4e0efinally\u8fde\u7528\uff0c\u4ece\u8bed\u6cd5\u4e0a\u8bb2finally\u5fc5\u987b\u653e\u5230else\u4e4b\u540e\uff0c\u4f46\u53ef\u4ee5\u4f7f\u7528try-except-finally\u7684\u5f62\u5f0f\uff0c\u4e5f\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528try-finally\u7684\u5f62\u5f0f\u3002\u65e0\u8bba\u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\u662f\u5426\u89e6\u53d1\u5f02\u5e38\uff0c\u90fd\u4f1a\u6267\u884cfinally\u7684\u5b50\u4ee3\u7801\u5757\uff0c\u56e0\u6b64\u901a\u5e38\u5728finally\u7684\u5b50\u4ee3\u7801\u5757\u505a\u4e00\u4e9b\u56de\u6536\u8d44\u6e90\u7684\u64cd\u4f5c\uff0c\u6bd4\u5982\u5173\u95ed\u6253\u5f00\u7684\u6587\u4ef6\u3001\u5173\u95ed\u6570\u636e\u5e93\u8fde\u63a5\u7b49<\/p>\n<pre><code class=\"language-python\">try:\n    \u88ab\u68c0\u6d4b\u7684\u4ee3\u7801\u5757\nexcept \u5f02\u5e38\u7c7b\u578b1:\n    pass\nexcept \u5f02\u5e38\u7c7b\u578b2:\n    pass\n......\nelse:\n    \u6ca1\u6709\u5f02\u5e38\u53d1\u751f\u65f6\u6267\u884c\u7684\u4ee3\u7801\u5757\nfinally:\n    \u65e0\u8bba\u6709\u65e0\u5f02\u5e38\u53d1\u751f\u90fd\u4f1a\u6267\u884c\u7684\u4ee3\u7801\u5757<\/code><\/pre>\n<p>\u4e3e\u4f8b<\/p>\n<pre><code class=\"language-python\">f=None\ntry:\n    f=open(\u2018db.txt\u2019,&#039;r&#039;,encoding=&#039;utf-8&#039;)\n    s=f.read().strip()\n    int(s)  # \u82e5\u5b57\u7b26\u4e32s\u4e2d\u5305\u542b\u975e\u6570\u5b57\u65f6\u5219\u4f1a\u89e6\u53d1\u5f02\u5e38ValueError\n    # f.close() # \u82e5\u4e0a\u9762\u7684\u4ee3\u7801\u89e6\u53d1\u5f02\u5e38\uff0c\u5219\u6839\u672c\u4e0d\u53ef\u80fd\u6267\u884c\u5230\u6b64\u5904\u7684\u4ee3\u7801\uff0c\u5e94\u8be5\u5c06\u5173\u95ed\u6587\u4ef6\u7684\u64cd\u4f5c\u653e\u5230finally\u4e2d\nfinally:\n    if f: # \u6587\u4ef6\u5b58\u5728\u5219f\u7684\u503c\u4e0d\u4e3aNone\n        f.close()<\/code><\/pre>\n<p>\u5728\u4e0d\u7b26\u5408Python\u89e3\u91ca\u5668\u7684\u8bed\u6cd5\u6216\u903b\u8f91\u89c4\u5219\u65f6\uff0c\u662f\u7531Python\u89e3\u91ca\u5668\u4e3b\u52a8\u89e6\u53d1\u7684\u5404\u79cd\u7c7b\u578b\u7684\u5f02\u5e38\uff0c\u800c\u5bf9\u4e8e\u8fdd\u53cd\u7a0b\u5e8f\u5458\u81ea\u5b9a\u5236\u7684\u5404\u7c7b\u89c4\u5219\uff0c\u5219\u9700\u8981\u7531\u7a0b\u5e8f\u5458\u81ea\u5df1\u6765\u660e\u786e\u5730\u89e6\u53d1\u5f02\u5e38\uff0c\u8fd9\u5c31\u7528\u5230\u4e86raise\u8bed\u53e5\uff0craise\u540e\u5fc5\u987b\u662f\u4e00\u4e2a\u5f02\u5e38\u7684\u7c7b\u6216\u8005\u662f\u5f02\u5e38\u7684\u5b9e\u4f8b<\/p>\n<pre><code class=\"language-python\">class Student:\n    def __init__(self,name,age):\n        if not isinstance(name,str):\n            raise TypeError(&#039;name must be str&#039;)\n        if not isinstance(age,int):\n            raise TypeError(&#039;age must be int&#039;)\n\n        self.name=name\n        self.age=age\n\nstu1=Student(4573,18) # TypeError: name must be str\nstu2=Student(&#039;egon&#039;,&#039;18&#039;) # TypeError: age must be int<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe05.png'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe05.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>\u5728\u5185\u7f6e\u5f02\u5e38\u4e0d\u591f\u7528\u7684\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u7ee7\u627f\u5185\u7f6e\u7684\u5f02\u5e38\u7c7b\u6765\u81ea\u5b9a\u4e49\u5f02\u5e38\u7c7b<\/p>\n<pre><code class=\"language-python\">class PoolEmptyError(Exception): # \u53ef\u4ee5\u901a\u8fc7\u7ee7\u627fException\u6765\u5b9a\u4e49\u4e00\u4e2a\u5168\u65b0\u7684\u5f02\u5e38\n    def __init__(self,value=&#039;The proxy source is exhausted&#039;): # \u53ef\u4ee5\u5b9a\u5236\u521d\u59cb\u5316\u65b9\u6cd5\n        super(PoolEmptyError,self).__init__()\n        self.value=value\n\n    def __str__(self): # \u53ef\u4ee5\u5b9a\u4e49\u8be5\u65b9\u6cd5\u7528\u6765\u5b9a\u5236\u89e6\u53d1\u5f02\u5e38\u65f6\u6253\u5370\u5f02\u5e38\u503c\u7684\u683c\u5f0f\n        return &#039;&lt; %s &gt;&#039; %self.value\n\nclass NetworkIOError(IOError): # \u4e5f\u53ef\u4ee5\u5728\u7279\u5b9a\u5f02\u5e38\u7684\u57fa\u7840\u4e0a\u6269\u5c55\u4e00\u4e2a\u76f8\u5173\u7684\u5f02\u5e38\n    pass\n\nraise PoolEmptyError # __main__.PoolEmptyError: &lt; The proxy source is exhausted &gt;\nraise NetworkIOError(&#039;\u8fde\u63a5\u88ab\u62d2\u7edd&#039;) # __main__.NetworkIOError: \u8fde\u63a5\u88ab\u62d2\u7edd<\/code><\/pre>\n<p>\u6700\u540e\uff0cPython\u8fd8\u63d0\u4f9b\u4e86\u4e00\u4e2a\u65ad\u8a00\u8bed\u53e5assert expression\uff0c\u65ad\u5b9a\u8868\u8fbe\u5f0fexpression\u6210\u7acb\uff0c\u5426\u5219\u89e6\u53d1\u5f02\u5e38AssertionError\uff0c\u4e0eraise-if-not\u7684\u8bed\u4e49\u76f8\u540c\uff0c\u5982\u4e0b<\/p>\n<pre><code class=\"language-python\">age=&#039;18&#039;\n\n# \u82e5\u8868\u8fbe\u5f0fisinstance(age,int)\u8fd4\u56de\u503c\u4e3aFalse\u5219\u89e6\u53d1\u5f02\u5e38AssertionError\nassert isinstance(age,int)\n\n# \u7b49\u540c\u4e8e\nif not isinstance(age,int):\n    raise AssertionError<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe06-2.jpeg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe06-2.jpeg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<h1>\u4e09 \u4f55\u65f6\u4f7f\u7528\u5f02\u5e38\u5904\u7406<\/h1>\n<p>\u5728\u4e86\u89e3\u4e86\u5f02\u5e38\u5904\u7406\u673a\u5236\u540e\uff0c\u672c\u7740\u63d0\u9ad8\u7a0b\u5e8f\u5bb9\u9519\u6027\u548c\u53ef\u9760\u6027\u7684\u76ee\u7684\uff0c\u8bfb\u8005\u53ef\u80fd\u4f1a\u9519\u8bef\u5730\u8ba4\u4e3a\u5e94\u8be5\u5c3d\u53ef\u80fd\u591a\u5730\u4e3a\u7a0b\u5e8f\u52a0\u4e0atry&#8230;except&#8230;\uff0c\u8fd9\u5176\u662f\u5728\u8fc7\u5ea6\u6d88\u8d39\u7a0b\u5e8f\u7684\u53ef\u8bfb\u6027\uff0c\u56e0\u4e3atry&#8230;except\u672c\u6765\u5c31\u662f\u4f60\u9644\u52a0\u7ed9\u7a0b\u5e8f\u7684\u4e00\u79cd\u989d\u5916\u7684\u903b\u8f91\uff0c\u4e0e\u4f60\u7684\u4e3b\u8981\u5de5\u4f5c\u662f\u6ca1\u6709\u591a\u5927\u5173\u7cfb\u7684\u3002<\/p>\n<p>\u200b   \u5982\u679c\u9519\u8bef\u53d1\u751f\u7684\u6761\u4ef6\u662f\u201c\u53ef\u9884\u77e5\u7684\u201d\uff0c\u6211\u4eec\u5e94\u8be5\u7528if\u6765\u8fdb\u884c\u201d\u9884\u9632\u201d\uff0c\u5982\u4e0b<\/p>\n<pre><code class=\"language-python\">age=input(&#039;input your age&gt;&gt;: &#039;).strip()\nif age.isdigit(): # \u53ef\u9884\u77e5\u53ea\u6709\u6ee1\u8db3\u5b57\u7b26\u4e32age\u662f\u6570\u5b57\u7684\u6761\u4ef6\uff0cint(age)\u624d\u4e0d\u4f1a\u89e6\u53d1\u5f02\u5e38\uff0c\n    age=int(age)\nelse:\n    print(&#039;You must enter the number&#039;)<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe07-2.jpeg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/\u6076\u641e\u56fe07-2.jpeg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>\u5982\u679c\u9519\u8bef\u53d1\u751f\u7684\u6761\u4ef6\u201c\u4e0d\u53ef\u9884\u77e5\u201d\uff0c\u5373\u5f02\u5e38\u4e00\u5b9a\u4f1a\u89e6\u53d1\uff0c\u90a3\u4e48\u6211\u4eec\u624d\u5e94\u8be5\u4f7f\u7528try&#8230;except\u8bed\u53e5\u6765\u5904\u7406\u3002\u4f8b\u5982\u6211\u4eec\u7f16\u5199\u4e00\u4e2a\u4e0b\u8f7d\u7f51\u9875\u5185\u5bb9\u7684\u529f\u80fd\uff0c\u7f51\u7edc\u53d1\u751f\u5ef6\u8fdf\u4e4b\u7c7b\u7684\u5f02\u5e38\u662f\u5f88\u6b63\u5e38\u7684\u4e8b\uff0c\u800c\u6211\u4eec\u6839\u672c\u65e0\u6cd5\u9884\u77e5\u5728\u6ee1\u8db3\u4ec0\u4e48\u6761\u4ef6\u7684\u60c5\u51b5\u4e0b\u624d\u4f1a\u51fa\u73b0\u5ef6\u8fdf\uff0c\u56e0\u800c\u53ea\u80fd\u7528\u5f02\u5e38\u5904\u7406\u673a\u5236\u4e86<\/p>\n<pre><code class=\"language-python\">import requests\nfrom requests.exceptions import ConnectTimeout # \u5bfc\u5165requests\u6a21\u5757\u5185\u81ea\u5b9a\u4e49\u7684\u5f02\u5e38\n\ndef get(url):\n    try:\n        response=requests.get(url,timeout=3)#\u8d85\u8fc73\u79d2\u672a\u4e0b\u8f7d\u6210\u529f\u5219\u89e6\u53d1ConnectTimeout\u5f02\u5e38\n        res=response.text\n    except ConnectTimeout:\n        print(&#039;\u8fde\u63a5\u8bf7\u6c42\u8d85\u65f6&#039;)\n        res=None\n    except Exception:\n        print(&#039;\u7f51\u7edc\u51fa\u73b0\u5176\u4ed6\u5f02\u5e38&#039;)\n        res=None\n    return res\n\nget(&#039;https:\/\/www.python.org&#039;)<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/01-47-\u5b66\u4e60.jpg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2022\/03\/01-47-\u5b66\u4e60.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00 \u4ec0\u4e48\u662f\u5f02\u5e38 \u5f02\u5e38\u662f\u7a0b\u5e8f\u53d1\u751f\u9519\u8bef\u7684\u4fe1\u53f7\u3002\u7a0b\u5e8f\u4e00\u65e6\u51fa\u73b0\u9519\u8bef\uff0c\u4fbf\u4f1a\u4ea7\u751f\u4e00\u4e2a\u5f02\u5e38\uff0c\u82e5\u7a0b\u5e8f\u4e2d\u6ca1\u6709\u5904\u7406\u5b83\uff0c\u5c31\u4f1a\u629b\u51fa\u8be5\u5f02 [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":6723,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[3,281,329],"tags":[],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/4331"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4331"}],"version-history":[{"count":0,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/4331\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/media\/6723"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4331"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4331"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4331"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}