{"id":1666,"date":"2020-06-22T04:16:21","date_gmt":"2020-06-21T20:16:21","guid":{"rendered":"http:\/\/39.97.231.10\/?p=1666"},"modified":"2022-03-19T02:03:07","modified_gmt":"2022-03-18T18:03:07","slug":"python%e5%a5%bd%e7%94%a8%e7%9a%84%e5%86%85%e7%bd%ae%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"http:\/\/www.weijing.co\/?p=1666","title":{"rendered":"Python\u5185\u7f6e\u51fd\u6570"},"content":{"rendered":"<div>\n<div>\n<div>python\u4e2d\u6709\u8bb8\u591a\u5185\u7f6e\u51fd\u6570\uff0c\u4e0d\u50cfprint\u90a3\u4e48\u5e7f\u4e3a\u4eba\u77e5\uff0c\u4f46\u5b83\u4eec\u5374\u5f02\u5e38\u7684\u5f3a\u5927\uff0c\u7528\u597d\u4e86\u53ef\u4ee5\u5927\u5927\u63d0\u9ad8\u4ee3\u7801\u6548\u7387\u3002<\/div>\n<\/div>\n<\/div>\n<article>\u8fd9\u6b21\u6765\u68b3\u7406\u4e0b8\u4e2a\u597d\u7528\u7684python\u5185\u7f6e\u51fd\u6570\u3002<\/p>\n<h2>1\u3001set()<\/h2>\n<p>\u5f53\u9700\u8981\u5bf9\u4e00\u4e2a\u5217\u8868\u8fdb\u884c\u53bb\u91cd\u64cd\u4f5c\u7684\u65f6\u5019\uff0cset()\u51fd\u6570\u5c31\u6d3e\u4e0a\u7528\u573a\u4e86\u3002<\/p>\n<div>\n<pre>obj = [\\'a\\',\\'b\\',\\'c\\',\\'b\\',\\'a\\']\nprint(set(obj))\n# \u8f93\u51fa\uff1a{\\'b\\', \\'c\\', \\'a\\'}\n<\/pre>\n<\/div>\n<p>set([iterable])\u7528\u4e8e\u521b\u5efa\u4e00\u4e2a\u96c6\u5408\uff0c\u96c6\u5408\u91cc\u7684\u5143\u7d20\u662f\u65e0\u5e8f\u4e14\u4e0d\u91cd\u590d\u7684\u3002<br \/>\n\u96c6\u5408\u5bf9\u8c61\u521b\u5efa\u540e\uff0c\u8fd8\u80fd\u4f7f\u7528\u5e76\u96c6\u3001\u4ea4\u96c6\u3001\u5dee\u96c6\u529f\u80fd\u3002<button type=\\\"button\\\" aria-label=\\\"\u590d\u5236\u4ee3\u7801\\\"><\/button><\/p>\n<div>\n<pre>A = set(\\'hello\\')\nB = set(\\'world\\')\nA.union(B) # \u5e76\u96c6\uff0c\u8f93\u51fa\uff1a{\\'d\\', \\'e\\', \\'h\\', \\'l\\', \\'o\\', \\'r\\', \\'w\\'}\nA.intersection(B) # \u4ea4\u96c6\uff0c\u8f93\u51fa\uff1a{\\'l\\', \\'o\\'}\nA.difference(B) # \u5dee\u96c6\uff0c\u8f93\u51fa\uff1a{\\'d\\', \\'r\\', \\'w\\'}\n<\/pre>\n<\/div>\n<h2>2\u3001eval()<\/h2>\n<p>\u4e4b\u524d\u6709\u4eba\u95ee\u5982\u4f55\u7528python\u5199\u4e00\u4e2a\u56db\u5219\u8fd0\u7b97\u5668\uff0c\u8f93\u5165\u5b57\u7b26\u4e32\u516c\u5f0f\uff0c\u76f4\u63a5\u4ea7\u751f\u7ed3\u679c\u3002<br \/>\n\u7528eval()\u6765\u505a\u5c31\u5f88\u7b80\u5355\uff1a<\/p>\n<div>\n<div>\n<div><\/div>\n<div data-width=\\\"418\\\" data-height=\\\"281\\\"><img src=\\\"https:\/\/upload-images.jianshu.io\/upload_images\/13723999-d756efd50e46616d.gif?imageMogr2\/auto-orient\/strip|imageView2\/2\/w\/418\/format\/webp\\\" data-original-src=\\\"\/\/upload-images.jianshu.io\/upload_images\/13723999-d756efd50e46616d.gif\\\" data-original-width=\\\"418\\\" data-original-height=\\\"281\\\" data-original-format=\\\"image\/gif\\\" data-original-filesize=\\\"16193\\\" data-image-index=\\\"0\\\" \/><\/div>\n<\/div>\n<\/div>\n<p>eval(str_expression)\u4f5c\u7528\u662f\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u6210\u8868\u8fbe\u5f0f\uff0c\u5e76\u4e14\u6267\u884c\u3002<\/p>\n<div>\n<pre>a = eval(\\'[1,2,3]\\')\nprint(type(a))\n# \u8f93\u51fa\uff1a&lt;class \\'list\\'&gt;\nb = eval(\\'max([2,4,5])\\')\nprint(b)\n# \u8f93\u51fa\uff1a 5\n<\/pre>\n<\/div>\n<h2>3\u3001sorted()<\/h2>\n<p>\u5728\u5904\u7406\u6570\u636e\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u7528\u5230\u6392\u5e8f\u64cd\u4f5c\uff0c\u6bd4\u5982\u5c06\u5217\u8868\u3001\u5b57\u5178\u3001\u5143\u7ec4\u91cc\u9762\u7684\u5143\u7d20\u6b63\/\u5012\u6392\u5e8f\u3002<br \/>\n\u8fd9\u65f6\u5019\u5c31\u9700\u8981\u7528\u5230sorted()\u00a0\uff0c\u5b83\u53ef\u4ee5\u5bf9\u4efb\u4f55\u53ef\u8fed\u4ee3\u5bf9\u8c61\u8fdb\u884c\u6392\u5e8f\uff0c\u5e76\u8fd4\u56de\u5217\u8868\u3002<br \/>\n\u5bf9\u5217\u8868\u5347\u5e8f\u64cd\u4f5c\uff1a<\/p>\n<div>\n<pre>a = sorted([2,4,3,7,1,9])\nprint(a)\n# \u8f93\u51fa\uff1a[1, 2, 3, 4, 7, 9]\n<\/pre>\n<\/div>\n<p>\u5bf9\u5143\u7ec4\u5012\u5e8f\u64cd\u4f5c\uff1a<\/p>\n<div>\n<pre>sorted((4,1,9,6),reverse=True)\nprint(a)\n# \u8f93\u51fa\uff1a[9, 6, 4, 1]\n<\/pre>\n<\/div>\n<p>\u4f7f\u7528\u53c2\u6570\uff1akey\uff0c\u6839\u636e\u81ea\u5b9a\u4e49\u89c4\u5219\uff0c\u6309\u5b57\u7b26\u4e32\u957f\u5ea6\u6765\u6392\u5e8f\uff1a<\/p>\n<div>\n<pre>chars = [\\'apple\\',\\'watermelon\\',\\'pear\\',\\'banana\\']\na = sorted(chars,key=lambda x:len(x))\nprint(a)\n# \u8f93\u51fa\uff1a[\\'pear\\', \\'apple\\', \\'banana\\', \\'watermelon\\']\n<\/pre>\n<\/div>\n<p>\u6839\u636e\u81ea\u5b9a\u4e49\u89c4\u5219\uff0c\u5bf9\u5143\u7ec4\u6784\u6210\u7684\u5217\u8868\u8fdb\u884c\u6392\u5e8f\uff1a<\/p>\n<div>\n<pre>tuple_list = [(\\'A\\', 1,5), (\\'B\\', 3,2), (\\'C\\', 2,6)]\n# key=lambda x: x[1]\u4e2d\u53ef\u4ee5\u4efb\u610f\u9009\u5b9ax\u4e2d\u53ef\u9009\u7684\u4f4d\u7f6e\u8fdb\u884c\u6392\u5e8f\na = sorted(tuple_list, key=lambda x: x[1])\nprint(a)\n# \u8f93\u51fa\uff1a[(\\'A\\', 1, 5), (\\'C\\', 2, 6), (\\'B\\', 3, 2)]\n<\/pre>\n<\/div>\n<h2>4\u3001reversed()<\/h2>\n<p>\u5982\u679c\u9700\u8981\u5bf9\u5e8f\u5217\u7684\u5143\u7d20\u8fdb\u884c\u53cd\u8f6c\u64cd\u4f5c\uff0creversed()\u51fd\u6570\u80fd\u5e2e\u5230\u4f60\u3002<br \/>\nreversed()\u63a5\u53d7\u4e00\u4e2a\u5e8f\u5217\uff0c\u5c06\u5e8f\u5217\u91cc\u7684\u5143\u7d20\u53cd\u8f6c\uff0c\u5e76\u6700\u7ec8\u8fd4\u56de\u8fed\u4ee3\u5668\u3002<\/p>\n<div>\n<pre>a = reversed(\\'abcde\\')\nprint(list(a))\n# \u8f93\u51fa\uff1a[\\'e\\', \\'d\\', \\'c\\', \\'b\\', \\'a\\']\nb = reversed([2,3,4,5])\nprint(list(b))\n# \u8f93\u51fa\uff1a[5, 4, 3, 2]\n<\/pre>\n<\/div>\n<h2>5\u3001map()<\/h2>\n<p>\u505a\u6587\u672c\u5904\u7406\u7684\u65f6\u5019\uff0c\u5047\u5982\u8981\u5bf9\u5e8f\u5217\u91cc\u7684\u6bcf\u4e2a\u5355\u8bcd\u8fdb\u884c\u5927\u5199\u8f6c\u5316\u64cd\u4f5c\u3002<br \/>\n\u8fd9\u4e2a\u65f6\u5019\u5c31\u53ef\u4ee5\u4f7f\u7528map()\u51fd\u6570\u3002<\/p>\n<div>\n<pre>chars = [\\'apple\\',\\'watermelon\\',\\'pear\\',\\'banana\\']\na = map(lambda x:x.upper(),chars)\nprint(list(a))\n# \u8f93\u51fa\uff1a[\\'APPLE\\', \\'WATERMELON\\', \\'PEAR\\', \\'BANANA\\']\n<\/pre>\n<\/div>\n<p>map()\u4f1a\u6839\u636e\u63d0\u4f9b\u7684\u51fd\u6570\uff0c\u5bf9\u6307\u5b9a\u7684\u5e8f\u5217\u505a\u6620\u5c04\uff0c\u6700\u7ec8\u8fd4\u56de\u8fed\u4ee3\u5668\u3002<br \/>\n\u4e5f\u5c31\u662f\u8bf4map()\u51fd\u6570\u4f1a\u628a\u5e8f\u5217\u91cc\u7684\u6bcf\u4e00\u4e2a\u5143\u7d20\u7528\u6307\u5b9a\u7684\u65b9\u6cd5\u52a0\u5de5\u4e00\u904d\uff0c\u6700\u7ec8\u8fd4\u56de\u7ed9\u4f60\u52a0\u5de5\u597d\u7684\u5e8f\u5217\u3002<br \/>\n\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u5bf9\u5217\u8868\u91cc\u7684\u6bcf\u4e2a\u6570\u5b57\u4f5c\u5e73\u65b9\u5904\u7406\uff1a<\/p>\n<div>\n<pre>nums = [1,2,3,4]\na = map(lambda x:x*x,nums)\nprint(list(a))\n# \u8f93\u51fa\uff1a[1, 4, 9, 16]\n<\/pre>\n<\/div>\n<h2>6\u3001reduce()<\/h2>\n<p>\u524d\u9762\u8bf4\u5230\u5bf9\u5217\u8868\u91cc\u7684\u6bcf\u4e2a\u6570\u5b57\u4f5c\u5e73\u65b9\u5904\u7406\uff0c\u7528map()\u51fd\u6570\u3002<br \/>\n\u90a3\u6211\u60f3\u5c06\u5217\u8868\u91cc\u7684\u6bcf\u4e2a\u5143\u7d20\u76f8\u4e58\uff0c\u8be5\u600e\u4e48\u505a\u5462\uff1f<br \/>\n\u8fd9\u65f6\u5019\u7528\u5230reduce()\u51fd\u6570\u3002<\/p>\n<div>\n<pre>from functools import reduce\nnums = [1,2,3,4]\na = reduce(lambda x,y:x*y,nums)\nprint(a)\n# \u8f93\u51fa\uff1a24\n<\/pre>\n<\/div>\n<p>reduce()\u4f1a\u5bf9\u53c2\u6570\u5e8f\u5217\u4e2d\u5143\u7d20\u8fdb\u884c\u7d2f\u79ef\u3002<br \/>\n\u7b2c\u4e00\u3001\u7b2c\u4e8c\u4e2a\u5143\u7d20\u5148\u8fdb\u884c\u51fd\u6570\u64cd\u4f5c\uff0c\u751f\u6210\u7684\u7ed3\u679c\u518d\u548c\u7b2c\u4e09\u4e2a\u5143\u7d20\u8fdb\u884c\u51fd\u6570\u64cd\u4f5c\uff0c\u4ee5\u6b64\u7c7b\u63a8\uff0c\u6700\u7ec8\u751f\u6210\u6240\u6709\u5143\u7d20\u7d2f\u79ef\u8fd0\u7b97\u7684\u7ed3\u679c\u3002<br \/>\n\u518d\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u5c06\u5b57\u6bcd\u8fde\u63a5\u6210\u5b57\u7b26\u4e32\u3002<\/p>\n<div>\n<pre>from functools import reduce\nchars = [\\'a\\',\\'p\\',\\'p\\',\\'l\\',\\'e\\']\na = reduce(lambda x,y:x+y,chars)\nprint(a)\n# \u8f93\u51fa\uff1aapple\n<\/pre>\n<\/div>\n<p>\u4f60\u53ef\u80fd\u5df2\u7ecf\u6ce8\u610f\u5230\uff0creduce()\u51fd\u6570\u5728python3\u91cc\u5df2\u7ecf\u4e0d\u518d\u662f\u5185\u7f6e\u51fd\u6570\uff0c\u800c\u662f\u8fc1\u79fb\u5230\u4e86functools\u6a21\u5757\u4e2d\u3002<br \/>\n\u8fd9\u91cc\u628areduce()\u51fd\u6570\u62ce\u51fa\u6765\u8bb2\uff0c\u662f\u56e0\u4e3a\u5b83\u592a\u91cd\u8981\u4e86\u3002<\/p>\n<h2>7\u3001filter()<\/h2>\n<p>\u4e00\u4e9b\u6570\u5b57\u7ec4\u6210\u7684\u5217\u8868\uff0c\u8981\u628a\u5176\u4e2d\u5076\u6570\u53bb\u6389\uff0c\u8be5\u600e\u4e48\u505a\u5462\uff1f<\/p>\n<div>\n<pre>nums = [1,2,3,4,5,6]\na = filter(lambda x:x%2!=0,nums)\nprint(list(a))\n# \u8f93\u51fa\uff1a[1,3,5]\n<\/pre>\n<\/div>\n<p>filter()\u51fd\u6570\u8f7b\u677e\u5b8c\u6210\u4e86\u4efb\u52a1\uff0c\u5b83\u7528\u4e8e\u8fc7\u6ee4\u5e8f\u5217\uff0c\u8fc7\u6ee4\u6389\u4e0d\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20\uff0c\u8fd4\u56de\u4e00\u4e2a\u8fed\u4ee3\u5668\u5bf9\u8c61\u3002<br \/>\nfilter()\u51fd\u6570\u548cmap()\u3001reduce()\u51fd\u6570\u7c7b\u4f3c\uff0c\u90fd\u662f\u5c06\u5e8f\u5217\u91cc\u7684\u6bcf\u4e2a\u5143\u7d20\u6620\u5c04\u5230\u51fd\u6570\uff0c\u6700\u7ec8\u8fd4\u56de\u7ed3\u679c\u3002<br \/>\n\u6211\u4eec\u518d\u8bd5\u8bd5\uff0c\u5982\u4f55\u4ece\u8bb8\u591a\u5355\u8bcd\u91cc\u6311\u51fa\u5305\u542b\u5b57\u6bcdw\u7684\u5355\u8bcd\u3002<\/p>\n<div>\n<pre>chars = chars = [\\'apple\\',\\'watermelon\\',\\'pear\\',\\'banana\\']\na = filter(lambda x:\\'w\\' in x,chars)\nprint(list(a))\n# \u8f93\u51fa\uff1a[\\'watermelon\\']\n<\/pre>\n<\/div>\n<h2>8\u3001enumerate()<\/h2>\n<p>\u8fd9\u6837\u4e00\u4e2a\u573a\u666f\uff0c\u540c\u65f6\u6253\u5370\u51fa\u5e8f\u5217\u91cc\u6bcf\u4e00\u4e2a\u5143\u7d20\u548c\u5b83\u5bf9\u5e94\u7684\u987a\u5e8f\u53f7\uff0c\u6211\u4eec\u7528enumerate()\u51fd\u6570\u505a\u505a\u770b\u3002<\/p>\n<div>\n<pre>chars = [\\'apple\\',\\'watermelon\\',\\'pear\\',\\'banana\\']\nfor i,j in enumerate(chars):\n    print(i,j)\n\\'\\'\\'\n\u8f93\u51fa\uff1a\n0 apple\n1 watermelon\n2 pear\n3 banana\n\\'\\'\\'\n<\/pre>\n<\/div>\n<p>enumerate\u7ffb\u8bd1\u8fc7\u6765\u662f\u679a\u4e3e\u3001\u5217\u4e3e\u7684\u610f\u601d\uff0c\u6240\u4ee5\u8bf4enumerate()\u51fd\u6570\u7528\u4e8e\u5bf9\u5e8f\u5217\u91cc\u7684\u5143\u7d20\u8fdb\u884c\u987a\u5e8f\u6807\u6ce8\uff0c\u8fd4\u56de(\u5143\u7d20\u3001\u7d22\u5f15)\u7ec4\u6210\u7684\u8fed\u4ee3\u5668\u3002<br \/>\n\u518d\u4e3e\u4e2a\u4f8b\u5b50\u8bf4\u660e\uff0c\u5bf9\u5b57\u7b26\u4e32\u8fdb\u884c\u6807\u6ce8\uff0c\u8fd4\u56de\u6bcf\u4e2a\u5b57\u6bcd\u548c\u5176\u7d22\u5f15\u3002<\/p>\n<div>\n<pre>a = enumerate(\\'abcd\\')\nprint(list(a))\n# \u8f93\u51fa\uff1a[(0, \\'a\\'), (1, \\'b\\'), (2, \\'c\\'), (3, \\'d\\')]<\/pre>\n<\/div>\n<\/article>\n","protected":false},"excerpt":{"rendered":"<p>python\u4e2d\u6709\u8bb8\u591a\u5185\u7f6e\u51fd\u6570\uff0c\u4e0d\u50cfprint\u90a3\u4e48\u5e7f\u4e3a\u4eba\u77e5\uff0c\u4f46\u5b83\u4eec\u5374\u5f02\u5e38\u7684\u5f3a\u5927\uff0c\u7528\u597d\u4e86\u53ef\u4ee5\u5927\u5927\u63d0\u9ad8\u4ee3\u7801\u6548\u7387\u3002 \u8fd9 &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"http:\/\/www.weijing.co\/?p=1666\"> <span class=\"screen-reader-text\">Python\u5185\u7f6e\u51fd\u6570<\/span> \u67e5\u770b\u5168\u6587 &raquo;<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":""},"categories":[106,126],"tags":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"mailpoet_newsletter_max":false,"woocommerce_thumbnail":false,"woocommerce_single":false,"woocommerce_gallery_thumbnail":false,"shop_catalog":false,"shop_single":false,"shop_thumbnail":false},"uagb_author_info":{"display_name":"weijing","author_link":"http:\/\/www.weijing.co\/?author=4"},"uagb_comment_info":0,"uagb_excerpt":"python\u4e2d\u6709\u8bb8\u591a\u5185\u7f6e\u51fd\u6570\uff0c\u4e0d\u50cfprint\u90a3\u4e48\u5e7f\u4e3a\u4eba\u77e5\uff0c\u4f46\u5b83\u4eec\u5374\u5f02\u5e38\u7684\u5f3a\u5927\uff0c\u7528\u597d\u4e86\u53ef\u4ee5\u5927\u5927\u63d0\u9ad8\u4ee3\u7801\u6548\u7387\u3002 \u8fd9&hellip;","_links":{"self":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/1666"}],"collection":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1666"}],"version-history":[{"count":1,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/1666\/revisions"}],"predecessor-version":[{"id":5507,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/1666\/revisions\/5507"}],"wp:attachment":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1666"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}