{"id":1784,"date":"2021-08-02T16:25:01","date_gmt":"2021-08-02T08:25:01","guid":{"rendered":"https:\/\/egonlin.com\/?p=1784"},"modified":"2022-02-07T17:12:29","modified_gmt":"2022-02-07T09:12:29","slug":"pandas","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=1784","title":{"rendered":"Pandas"},"content":{"rendered":"<h2>\u56db\u3001Pandas<\/h2>\n<ul>\n<li>\u7b80\u4ecb<\/li>\n<li>Series<\/li>\n<li>DataFrame<\/li>\n<li>\u65f6\u95f4\u5bf9\u8c61\u5904\u7406<\/li>\n<li>\u6570\u636e\u5206\u7ec4\u548c\u805a\u5408<\/li>\n<li>\u5176\u4ed6\u5e38\u7528\u65b9\u6cd5<\/li>\n<\/ul>\n<h3>1\u3001\u7b80\u4ecb<\/h3>\n<blockquote>\n<p>pandas\u662f\u4e00\u4e2a\u5f3a\u5927\u7684Python\u6570\u636e\u5206\u6790\u7684\u5de5\u5177\u5305\uff0c\u5b83\u662f\u57fa\u4e8eNumpy\u6784\u5efa\u7684\uff0c\u6b63\u56e0pandas\u7684\u51fa\u73b0\uff0c\u8ba9Python\u8bed\u8a00\u4e5f\u6210\u4e3a\u4f7f\u7528\u6700\u5e7f\u6cdb\u800c\u4e14\u5f3a\u5927\u7684\u6570\u636e\u5206\u6790\u73af\u5883\u4e4b\u4e00\u3002<\/p>\n<\/blockquote>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2021\/08\/\u6076\u641e\u56fe01-3.png'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2021\/08\/\u6076\u641e\u56fe01-3.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<p>Pandas\u7684\u4e3b\u8981\u529f\u80fd\uff1a<\/p>\n<ul>\n<li>\u5177\u5907\u5bf9\u5176\u529f\u80fd\u7684\u6570\u636e\u7ed3\u6784DataFrame\uff0cSeries<\/li>\n<li>\u96c6\u6210\u65f6\u95f4\u5e8f\u5217\u529f\u80fd<\/li>\n<li>\u63d0\u4f9b\u4e30\u5bcc\u7684\u6570\u5b66\u8fd0\u7b97\u548c\u64cd\u4f5c<\/li>\n<li>\u7075\u6d3b\u5904\u7406\u7f3a\u5931\u6570\u636e<\/li>\n<\/ul>\n<p>\u5b89\u88c5\u65b9\u6cd5\uff1a<\/p>\n<blockquote>\n<p>pip install pandas<\/p>\n<\/blockquote>\n<p>\u5f15\u7528\u65b9\u6cd5\uff1a<\/p>\n<blockquote>\n<p>import pandas as pd<\/p>\n<\/blockquote>\n<h3>2\u3001Series<\/h3>\n<p>Series\u662f\u4e00\u79cd\u7c7b\u4f3c\u4e8e\u4e00\u7ef4\u6570\u7ec4\u7684\u5bf9\u8c61\uff0c\u7531\u4e00\u7ec4\u6570\u636e\u548c\u4e00\u7ec4\u4e0e\u4e4b\u76f8\u5173\u7684\u6570\u636e\u6807\u7b7e(\u7d22\u5f15)\u7ec4\u6210<\/p>\n<blockquote>\n<p>1\u3001\u521b\u5efa\u65b9\u6cd5<\/p>\n<\/blockquote>\n<pre><code class=\"language-python\">\u7b2c\u4e00\u79cd\uff1a\npd.Series([4,5,6,7,8])\n\u6267\u884c\u7ed3\u679c\uff1a\n0    4\n1    5\n2    6\n3    7\n4    8\ndtype: int64\n# \u5c06\u6570\u7ec4\u7d22\u5f15\u4ee5\u53ca\u6570\u7ec4\u7684\u503c\u6253\u5370\u51fa\u6765\uff0c\u7d22\u5f15\u5728\u5de6\uff0c\u503c\u5728\u53f3\uff0c\u7531\u4e8e\u6ca1\u6709\u4e3a\u6570\u636e\u6307\u5b9a\u7d22\u5f15\uff0c\u4e8e\u662f\u4f1a\u81ea\u52a8\u521b\u5efa\u4e00\u4e2a0\u5230N-1\uff08N\u4e3a\u6570\u636e\u7684\u957f\u5ea6\uff09\u7684\u6574\u6570\u578b\u7d22\u5f15\uff0c\u53d6\u503c\u7684\u65f6\u5019\u53ef\u4ee5\u901a\u8fc7\u7d22\u5f15\u53d6\u503c\uff0c\u8ddf\u4e4b\u524d\u5b66\u8fc7\u7684\u6570\u7ec4\u548c\u5217\u8868\u4e00\u6837\n-----------------------------------------------\n\u7b2c\u4e8c\u79cd\uff1a\npd.Series([4,5,6,7,8],index=[&#039;a&#039;,&#039;b&#039;,&#039;c&#039;,&#039;d&#039;,&#039;e&#039;])\n\u6267\u884c\u7ed3\u679c\uff1a\na    4\nb    5\nc    6\nd    7\ne    8\ndtype: int64\n# \u81ea\u5b9a\u4e49\u7d22\u5f15\uff0cindex\u662f\u4e00\u4e2a\u7d22\u5f15\u5217\u8868\uff0c\u91cc\u9762\u5305\u542b\u7684\u662f\u5b57\u7b26\u4e32\uff0c\u4f9d\u7136\u53ef\u4ee5\u901a\u8fc7\u9ed8\u8ba4\u7d22\u5f15\u53d6\u503c\u3002\n-----------------------------------------------\n\u7b2c\u4e09\u79cd\uff1a\npd.Series({&quot;a&quot;:1,&quot;b&quot;:2})\n\u6267\u884c\u7ed3\u679c\uff1a\na    1\nb    2\ndtype: int64\n# \u6307\u5b9a\u7d22\u5f15\n-----------------------------------------------\n\u7b2c\u56db\u79cd\uff1a\npd.Series(0,index=[&#039;a&#039;,&#039;b&#039;,&#039;c&#039;])\n\u6267\u884c\u7ed3\u679c\uff1a\na    0\nb    0\nc    0\ndtype: int64\n# \u521b\u5efa\u4e00\u4e2a\u503c\u90fd\u662f0\u7684\u6570\u7ec4\n-----------------------------------------------<\/code><\/pre>\n<p>\u5bf9\u4e8eSeries\uff0c\u5176\u5b9e\u6211\u4eec\u53ef\u4ee5\u8ba4\u4e3a\u5b83\u662f\u4e00\u4e2a\u957f\u5ea6\u56fa\u5b9a\u4e14\u6709\u5e8f\u7684\u5b57\u5178\uff0c\u56e0\u4e3a\u5b83\u7684\u7d22\u5f15\u548c\u6570\u636e\u662f\u6309\u4f4d\u7f6e\u8fdb\u884c\u5339\u914d\u7684\uff0c\u50cf\u6211\u4eec\u4f1a\u4f7f\u7528\u5b57\u5178\u7684\u4e0a\u4e0b\u6587\uff0c\u5c31\u80af\u5b9a\u4e5f\u4f1a\u4f7f\u7528Series<\/p>\n<blockquote>\n<p>\u7f3a\u5931\u6570\u636e<\/p>\n<\/blockquote>\n<ul>\n<li>dropna()  # \u8fc7\u6ee4\u6389\u503c\u4e3aNaN\u7684\u884c<\/li>\n<li>fill()  # \u586b\u5145\u7f3a\u5931\u6570\u636e<\/li>\n<li>isnull()  # \u8fd4\u56de\u5e03\u5c14\u6570\u7ec4\uff0c\u7f3a\u5931\u503c\u5bf9\u5e94\u4e3aTrue<\/li>\n<li>notnull()  # \u8fd4\u56de\u5e03\u5c14\u6570\u7ec4\uff0c\u7f3a\u5931\u503c\u5bf9\u5e94\u4e3aFalse<\/li>\n<\/ul>\n<pre><code class=\"language-python\"># \u7b2c\u4e00\u6b65\uff0c\u521b\u5efa\u4e00\u4e2a\u5b57\u5178\uff0c\u901a\u8fc7Series\u65b9\u5f0f\u521b\u5efa\u4e00\u4e2aSeries\u5bf9\u8c61\n\nst = {&quot;sean&quot;:18,&quot;yang&quot;:19,&quot;bella&quot;:20,&quot;cloud&quot;:21}\nobj = pd.Series(st)\nobj\n\u8fd0\u884c\u7ed3\u679c\uff1a\nsean     18\nyang     19\nbella    20\ncloud    21\ndtype: int64\n------------------------------------------\n# \u7b2c\u4e8c\u6b65\na = {&#039;sean&#039;,&#039;yang&#039;,&#039;cloud&#039;,&#039;rocky&#039;}  # \u5b9a\u4e49\u4e00\u4e2a\u7d22\u5f15\u53d8\u91cf\n------------------------------------------\n#\u7b2c\u4e09\u6b65\nobj1 = pd.Series(st,index=a)\nobj1  # \u5c06\u7b2c\u4e8c\u6b65\u5b9a\u4e49\u7684a\u53d8\u91cf\u4f5c\u4e3a\u7d22\u5f15\u4f20\u5165\n\n# \u8fd0\u884c\u7ed3\u679c\uff1a\nrocky     NaN\ncloud    21.0\nsean     18.0\nyang     19.0\ndtype: float64\n# \u56e0\u4e3arocky\u6ca1\u6709\u51fa\u73b0\u5728st\u7684\u952e\u4e2d\uff0c\u6240\u4ee5\u8fd4\u56de\u7684\u662f\u7f3a\u5931\u503c<\/code><\/pre>\n<p>\u901a\u8fc7\u4e0a\u9762\u7684\u4ee3\u7801\u6f14\u793a\uff0c\u5bf9\u4e8e\u7f3a\u5931\u503c\u5df2\u7ecf\u6709\u4e86\u4e00\u4e2a\u7b80\u5355\u7684\u4e86\u89e3\uff0c\u63a5\u4e0b\u6765\u5c31\u6765\u770b\u770b\u5982\u4f55\u5224\u65ad\u7f3a\u5931\u503c<\/p>\n<pre><code class=\"language-python\">1\u3001\nobj1.isnull()  # \u662f\u7f3a\u5931\u503c\u8fd4\u56deTure\n\u8fd0\u884c\u7ed3\u679c\uff1a\nrocky     True\ncloud    False\nsean     False\nyang     False\ndtype: bool\n\n2\u3001\nobj1.notnull()  # \u4e0d\u662f\u7f3a\u5931\u503c\u8fd4\u56deTure\n\u8fd0\u884c\u7ed3\u679c\uff1a\nrocky    False\ncloud     True\nsean      True\nyang      True\ndtype: bool\n\n3\u3001\u8fc7\u6ee4\u7f3a\u5931\u503c # \u5e03\u5c14\u578b\u7d22\u5f15\nobj1[obj1.notnull()]\n\u8fd0\u884c\u7ed3\u679c\uff1a\ncloud    21.0\nyang     19.0\nsean     18.0\ndtype: float64<\/code><\/pre>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2021\/08\/05-07-\u5957\u8def.jpg'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2021\/08\/05-07-\u5957\u8def.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n<blockquote>\n<p>Series\u7279\u6027<\/p>\n<\/blockquote>\n<ul>\n<li>\u4ecendarray\u521b\u5efaSeries:Series(arr)<\/li>\n<li>\u4e0e\u6807\u91cf\uff08\u6570\u5b57\uff09\uff1asr * 2<\/li>\n<li>\u4e24\u4e2aSeries\u8fd0\u7b97<\/li>\n<li>\u901a\u7528\u51fd\u6570\uff1anp.ads(sr)<\/li>\n<li>\u5e03\u5c14\u503c\u8fc7\u6ee4\uff1asr[sr&gt;0]<\/li>\n<li>\u7edf\u8ba1\u51fd\u6570\uff1amean()\u3001sum()\u3001cumsum()<\/li>\n<\/ul>\n<p>\u652f\u6301\u5b57\u5178\u7684\u7279\u6027\uff1a<\/p>\n<ul>\n<li>\u4ece\u5b57\u5178\u521b\u5efaSeries\uff1aSeries(dic),<\/li>\n<li>In\u8fd0\u7b97\uff1a&#8217;a&#8217;in sr\u3001for x in sr<\/li>\n<li>\u952e\u7d22\u5f15\uff1asr[&#8216;a&#8217;],sr[[&#8216;a&#8217;,&#8217;b&#8217;,&#8217;d&#8217;]]<\/li>\n<li>\u952e\u5207\u7247\uff1asr[&#8216;a&#8217;:&#8217;c&#8217;]<\/li>\n<li>\u5176\u4ed6\u51fd\u6570\uff1aget(&#8216;a&#8217;,default=0)\u7b49<\/li>\n<\/ul>\n<blockquote>\n<p>\u6574\u6570\u7d22\u5f15<\/p>\n<\/blockquote>\n<p>pandas\u5f53\u4e2d\u7684\u6574\u6570\u7d22\u5f15\u5bf9\u8c61\u53ef\u80fd\u4f1a\u8ba9\u521d\u6b21\u63a5\u89e6\u5b83\u7684\u4eba\u5f88\u61f5\u903c\uff0c\u63a5\u4e0b\u6765\u901a\u8fc7\u4ee3\u7801\u6f14\u793a\uff1a<\/p><div 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[&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":2747,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[221],"tags":[216,226],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/1784"}],"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=1784"}],"version-history":[{"count":0,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/1784\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/media\/2747"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1784"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1784"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1784"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}