{"id":557,"date":"2024-12-26T22:57:01","date_gmt":"2024-12-26T14:57:01","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=557"},"modified":"2024-12-26T22:57:01","modified_gmt":"2024-12-26T14:57:01","slug":"%e5%a6%82%e4%bd%95%e5%9c%a8python%e4%b8%ad%e5%87%86%e7%a1%ae%e6%af%94%e8%be%83%e6%b5%ae%e7%82%b9%e6%95%b0%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2024\/12\/26\/%e5%a6%82%e4%bd%95%e5%9c%a8python%e4%b8%ad%e5%87%86%e7%a1%ae%e6%af%94%e8%be%83%e6%b5%ae%e7%82%b9%e6%95%b0%ef%bc%9f\/","title":{"rendered":"\u5982\u4f55\u5728Python\u4e2d\u51c6\u786e\u6bd4\u8f83\u6d6e\u70b9\u6570\uff1f"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u5728 Python \u4e2d\uff0c\u7531\u4e8e\u6d6e\u70b9\u6570\u7684\u5b58\u50a8\u65b9\u5f0f\u6709\u9650\uff0c\u76f4\u63a5\u6bd4\u8f83\u4e24\u4e2a\u6d6e\u70b9\u6570\u53ef\u80fd\u4f1a\u51fa\u73b0\u8bef\u5dee\u3002\u8fd9\u662f\u56e0\u4e3a\u6d6e\u70b9\u6570\u5728\u8ba1\u7b97\u673a\u4e2d\u5e76\u4e0d\u80fd\u7cbe\u786e\u8868\u793a\u67d0\u4e9b\u5c0f\u6570\u3002\u56e0\u6b64\uff0c\u4f7f\u7528\u5e38\u89c4\u7684\u6bd4\u8f83\uff08\u5982 <code>==<\/code>\uff09\u53ef\u80fd\u5bfc\u81f4\u4e0d\u51c6\u786e\u7684\u7ed3\u679c\u3002<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u901a\u5e38\u91c7\u7528\u4ee5\u4e0b\u51e0\u79cd\u65b9\u6cd5\u6765\u51c6\u786e\u6bd4\u8f83\u6d6e\u70b9\u6570\uff1a<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>1. \u4f7f\u7528\u5bb9\u5dee\u8303\u56f4\uff08<code>epsilon<\/code>\uff09\u8fdb\u884c\u6bd4\u8f83<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u7531\u4e8e\u6d6e\u70b9\u6570\u7684\u8868\u793a\u7cbe\u5ea6\u6709\u9650\uff0c\u6bd4\u8f83\u4e24\u4e2a\u6d6e\u70b9\u6570\u65f6\uff0c\u901a\u5e38\u4f1a\u68c0\u67e5\u5b83\u4eec\u7684\u5dee\u5f02\u662f\u5426\u5728\u4e00\u4e2a\u5141\u8bb8\u7684\u5bb9\u5dee\u8303\u56f4\u5185\u3002\u8fd9\u4e2a\u5bb9\u5dee\u503c\uff08\u901a\u5e38\u79f0\u4e3a <code>epsilon<\/code>\uff09\u662f\u4e00\u4e2a\u975e\u5e38\u5c0f\u7684\u6570\uff0c\u7528\u4e8e\u5224\u65ad\u4e24\u4e2a\u6d6e\u70b9\u6570\u662f\u5426\u201c\u8db3\u591f\u63a5\u8fd1\u201d\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>\u793a\u4f8b\uff1a\u4f7f\u7528\u5bb9\u5dee\u6bd4\u8f83\u6d6e\u70b9\u6570<\/strong><\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code># \u5b9a\u4e49\u5bb9\u5dee\u503c\nepsilon = 1e-9\n\n# \u6bd4\u8f83\u6d6e\u70b9\u6570\na = 0.1 + 0.2\nb = 0.3\n\nif abs(a - b) &lt; epsilon:\n    print(\"a \u548c b \u8db3\u591f\u63a5\u8fd1\uff0c\u8ba4\u4e3a\u5b83\u4eec\u76f8\u7b49\")\nelse:\n    print(\"a \u548c b \u4e0d\u76f8\u7b49\")<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c<code>abs(a - b)<\/code> \u8ba1\u7b97\u4e24\u4e2a\u6d6e\u70b9\u6570\u7684\u7edd\u5bf9\u5dee\uff0c\u5982\u679c\u8fd9\u4e2a\u5dee\u503c\u5c0f\u4e8e\u4e00\u4e2a\u9884\u8bbe\u7684\u5bb9\u5dee\uff08\u5982 <code>1e-9<\/code>\uff09\uff0c\u5c31\u8ba4\u4e3a\u5b83\u4eec\u76f8\u7b49\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>2. \u4f7f\u7528 <code>math.isclose()<\/code> \u51fd\u6570<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Python 3.5 \u5f15\u5165\u4e86 <code>math.isclose()<\/code> \u51fd\u6570\uff0c\u5b83\u7528\u4e8e\u5224\u65ad\u4e24\u4e2a\u6d6e\u70b9\u6570\u662f\u5426\u76f8\u7b49\uff0c\u5e76\u5141\u8bb8\u4f60\u8bbe\u7f6e\u76f8\u5bf9\u8bef\u5dee\u548c\u7edd\u5bf9\u8bef\u5dee\u7684\u5bb9\u5dee\u3002\u76f8\u6bd4\u624b\u52a8\u8ba1\u7b97\u5bb9\u5dee\u503c\uff0c<code>math.isclose()<\/code> \u66f4\u52a0\u7b80\u6d01\u4e14\u7b26\u5408\u5e38\u89c1\u7684\u6bd4\u8f83\u6807\u51c6\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>\u793a\u4f8b\uff1a\u4f7f\u7528 <code>math.isclose()<\/code> \u51fd\u6570\u6bd4\u8f83\u6d6e\u70b9\u6570<\/strong><\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>import math\n\n# \u5b9a\u4e49\u6d6e\u70b9\u6570\na = 0.1 + 0.2\nb = 0.3\n\n# \u4f7f\u7528 math.isclose() \u6bd4\u8f83\u6d6e\u70b9\u6570\nif math.isclose(a, b, rel_tol=1e-9):  # rel_tol \u662f\u76f8\u5bf9\u8bef\u5dee\uff0c\u9ed8\u8ba4\u662f 1e-9\n    print(\"a \u548c b \u8db3\u591f\u63a5\u8fd1\uff0c\u8ba4\u4e3a\u5b83\u4eec\u76f8\u7b49\")\nelse:\n    print(\"a \u548c b \u4e0d\u76f8\u7b49\")<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>rel_tol<\/code><\/strong>\uff1a\u76f8\u5bf9\u8bef\u5dee\uff0c\u8868\u793a\u4e24\u4e2a\u6d6e\u70b9\u6570\u5dee\u5f02\u7684\u6bd4\u4f8b\u3002<\/li>\n\n\n\n<li><strong><code>abs_tol<\/code><\/strong>\uff1a\u7edd\u5bf9\u8bef\u5dee\uff0c\u8868\u793a\u4e24\u4e2a\u6d6e\u70b9\u6570\u5dee\u5f02\u7684\u7edd\u5bf9\u503c\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><code>math.isclose()<\/code> \u4f1a\u6839\u636e\u8fd9\u4e24\u4e2a\u5bb9\u5dee\u503c\u5224\u65ad\u4e24\u4e2a\u6d6e\u70b9\u6570\u662f\u5426\u8db3\u591f\u63a5\u8fd1\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>3. \u7ed3\u5408\u76f8\u5bf9\u8bef\u5dee\u548c\u7edd\u5bf9\u8bef\u5dee<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u5355\u4e00\u7684\u5bb9\u5dee\u53ef\u80fd\u4e0d\u8db3\u4ee5\u51c6\u786e\u6bd4\u8f83\u6d6e\u70b9\u6570\uff0c\u7279\u522b\u662f\u5f53\u6570\u5b57\u63a5\u8fd1\u96f6\u65f6\u3002\u4f60\u53ef\u4ee5\u540c\u65f6\u4f7f\u7528\u76f8\u5bf9\u8bef\u5dee\uff08<code>rel_tol<\/code>\uff09\u548c\u7edd\u5bf9\u8bef\u5dee\uff08<code>abs_tol<\/code>\uff09\u6765\u8fdb\u884c\u66f4\u7cbe\u786e\u7684\u6bd4\u8f83\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>\u793a\u4f8b\uff1a\u7ed3\u5408\u76f8\u5bf9\u8bef\u5dee\u548c\u7edd\u5bf9\u8bef\u5dee\u8fdb\u884c\u6bd4\u8f83<\/strong><\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>import math\n\n# \u5b9a\u4e49\u6d6e\u70b9\u6570\na = 0.0000001\nb = 0.0000002\n\n# \u4f7f\u7528\u7edd\u5bf9\u8bef\u5dee\u548c\u76f8\u5bf9\u8bef\u5dee\u7684\u5bb9\u5dee\u8fdb\u884c\u6bd4\u8f83\nif math.isclose(a, b, rel_tol=1e-9, abs_tol=1e-9):\n    print(\"a \u548c b \u8db3\u591f\u63a5\u8fd1\uff0c\u8ba4\u4e3a\u5b83\u4eec\u76f8\u7b49\")\nelse:\n    print(\"a \u548c b \u4e0d\u76f8\u7b49\")<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>abs_tol<\/code><\/strong>\uff1a\u8bbe\u7f6e\u7edd\u5bf9\u8bef\u5dee\u5bb9\u5dee\uff0c\u5f53\u6d6e\u52a8\u8f83\u5c0f\u7684\u503c\u8fdb\u884c\u6bd4\u8f83\u65f6\uff0c\u5b83\u53ef\u4ee5\u786e\u4fdd\u5373\u4f7f\u5dee\u503c\u975e\u5e38\u5c0f\uff0c\u6bd4\u8f83\u7ed3\u679c\u4ecd\u7136\u5408\u7406\u3002<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>\u603b\u7ed3<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4f7f\u7528\u5bb9\u5dee\u6bd4\u8f83\u6d6e\u70b9\u6570<\/strong>\uff1a\u901a\u8fc7\u8bbe\u5b9a\u4e00\u4e2a\u975e\u5e38\u5c0f\u7684\u5bb9\u5dee\u503c\uff08<code>epsilon<\/code>\uff09\uff0c\u5224\u65ad\u4e24\u4e2a\u6d6e\u70b9\u6570\u7684\u5dee\u5f02\u662f\u5426\u5728\u5bb9\u5dee\u8303\u56f4\u5185\u3002<\/li>\n\n\n\n<li><strong>\u4f7f\u7528 <code>math.isclose()<\/code><\/strong>\uff1a\u8fd9\u662f\u6bd4\u8f83\u6d6e\u70b9\u6570\u7684\u63a8\u8350\u65b9\u6cd5\uff0c\u7b80\u5316\u4e86\u5bb9\u5dee\u503c\u8bbe\u7f6e\uff0c\u5e76\u63d0\u4f9b\u4e86\u76f8\u5bf9\u8bef\u5dee\u548c\u7edd\u5bf9\u8bef\u5dee\u9009\u9879\u3002<\/li>\n\n\n\n<li><strong>\u7ed3\u5408\u76f8\u5bf9\u8bef\u5dee\u548c\u7edd\u5bf9\u8bef\u5dee<\/strong>\uff1a\u5728\u8fdb\u884c\u6d6e\u70b9\u6570\u6bd4\u8f83\u65f6\uff0c\u5c24\u5176\u662f\u5f53\u503c\u975e\u5e38\u5c0f\u65f6\uff0c\u4f7f\u7528\u4e24\u8005\u7ed3\u5408\u6765\u83b7\u5f97\u66f4\u7cbe\u786e\u7684\u7ed3\u679c\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u8fc7\u8fd9\u4e9b\u65b9\u6cd5\uff0c\u4f60\u53ef\u4ee5\u907f\u514d\u76f4\u63a5\u6bd4\u8f83\u6d6e\u70b9\u6570\u65f6\u53ef\u80fd\u51fa\u73b0\u7684\u7cbe\u5ea6\u95ee\u9898\uff0c\u4ece\u800c\u8fdb\u884c\u66f4\u51c6\u786e\u7684\u6d6e\u70b9\u6570\u6bd4\u8f83\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Python \u4e2d\uff0c\u7531\u4e8e\u6d6e\u70b9\u6570\u7684\u5b58\u50a8\u65b9\u5f0f\u6709\u9650\uff0c\u76f4\u63a5\u6bd4\u8f83\u4e24\u4e2a\u6d6e\u70b9\u6570\u53ef\u80fd\u4f1a\u51fa\u73b0\u8bef\u5dee\u3002\u8fd9\u662f\u56e0\u4e3a\u6d6e\u70b9\u6570\u5728\u8ba1\u7b97\u673a\u4e2d\u5e76\u4e0d [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[54],"tags":[],"class_list":["post-557","post","type-post","status-publish","format-standard","hentry","category-python"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/557","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=557"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/557\/revisions"}],"predecessor-version":[{"id":558,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/557\/revisions\/558"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=557"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=557"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=557"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}