{"id":991165,"date":"2024-12-27T08:26:19","date_gmt":"2024-12-27T00:26:19","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/991165.html"},"modified":"2024-12-27T08:26:21","modified_gmt":"2024-12-27T00:26:21","slug":"python-pandas%e5%a6%82%e4%bd%95%e6%8f%90%e5%8f%96%e6%95%b0%e6%8d%ae","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/991165.html","title":{"rendered":"python pandas\u5982\u4f55\u63d0\u53d6\u6570\u636e"},"content":{"rendered":"

\"python<\/p>\n

\u4f7f\u7528Python Pandas\u63d0\u53d6\u6570\u636e\u7684\u6838\u5fc3\u65b9\u6cd5\u5305\u62ec\uff1a\u4f7f\u7528.loc[]\u548c.iloc[]\u8fdb\u884c\u7d22\u5f15\u3001\u4f7f\u7528\u6761\u4ef6\u7b5b\u9009\u6570\u636e\u3001\u5229\u7528query()\u51fd\u6570\u8fdb\u884c\u67e5\u8be2\u3001\u901a\u8fc7\u5b57\u7b26\u4e32\u65b9\u6cd5\u63d0\u53d6\u7279\u5b9a\u4fe1\u606f\u3002\u8fd9\u4e9b\u65b9\u6cd5\u53ef\u4ee5\u5e2e\u52a9\u7528\u6237\u9ad8\u6548\u5730\u4eceDataFrame\u4e2d\u63d0\u53d6\u6240\u9700\u7684\u6570\u636e\u3002\u4ee5\u4e0b\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u5982\u4f55\u4f7f\u7528.loc[]\u548c.iloc[]\u8fdb\u884c\u6570\u636e\u63d0\u53d6\u3002<\/strong><\/p>\n<\/p>\n

.loc[]\u548c.iloc[]\u7d22\u5f15\u65b9\u6cd5<\/strong><\/p>\n<\/p>\n

.loc[]\u662f\u57fa\u4e8e\u6807\u7b7e\uff08label\uff09\u7684\u7d22\u5f15\u65b9\u6cd5\uff0c\u800c.iloc[]\u662f\u57fa\u4e8e\u6574\u6570\u4f4d\u7f6e\uff08integer position\uff09\u7684\u7d22\u5f15\u65b9\u6cd5\u3002\u8fd9\u4e24\u8005\u662fPandas\u6700\u5e38\u7528\u7684\u6570\u636e\u63d0\u53d6\u65b9\u6cd5\u3002<\/p>\n<\/p>\n

    \n
  1. .loc[]\u7d22\u5f15<\/strong><\/li>\n<\/ol>\n

    .loc[]\u65b9\u6cd5\u53ef\u4ee5\u8ba9\u4f60\u901a\u8fc7\u884c\u6807\u7b7e\u548c\u5217\u6807\u7b7e\u6765\u63d0\u53d6\u6570\u636e\u3002\u8fd9\u4e2a\u65b9\u6cd5\u7279\u522b\u9002\u5408\u5904\u7406\u5e26\u6709\u7d22\u5f15\u6807\u7b7e\u7684DataFrame\u3002<\/p>\n<\/p>\n

    \u4f8b\u5982\uff0c\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2aDataFrame\u5982\u4e0b\uff1a<\/p>\n<\/p>\n

    import pandas as pd<\/p>\n
    data = {'Name': ['Alice', 'Bob', 'Charlie'],<\/p>\n
            'Age': [25, 30, 35],<\/p>\n
            'City': ['New York', 'Los Angeles', 'Chicago']}<\/p>\n
    df = pd.DataFrame(data, index=['A', 'B', 'C'])<\/p>\n
    <\/code><\/pre>\n<\/p>\n
    \u4f60\u53ef\u4ee5\u4f7f\u7528.loc[]\u6765\u63d0\u53d6\u67d0\u4e00\u884c\u6216\u67d0\u51e0\u5217\u7684\u6570\u636e\uff1a<\/p>\n<\/p>\n
    # \u63d0\u53d6\u5355\u884c<\/p>\n
    row_b = df.loc['B']<\/p>\n
    \u63d0\u53d6\u591a\u5217<\/strong><\/h2>\n
    name_and_city = df.loc[:, ['Name', 'City']]<\/p>\n
    <\/code><\/pre>\n<\/p>\n
    .loc[]\u7684\u5f3a\u5927\u4e4b\u5904\u5728\u4e8e\u5b83\u53ef\u4ee5\u7ed3\u5408\u5e03\u5c14\u6761\u4ef6\u6765\u7b5b\u9009\u6570\u636e\uff1a<\/p>\n<\/p>\n
    # \u63d0\u53d6\u5e74\u9f84\u5927\u4e8e28\u7684\u884c<\/p>\n
    age_above_28 = df.loc[df['Age'] > 28]<\/p>\n
    <\/code><\/pre>\n<\/p>\n
      \n
    1. .iloc[]\u7d22\u5f15<\/strong><\/li>\n<\/ol>\n
      .iloc[]\u65b9\u6cd5\u662f\u57fa\u4e8e\u6574\u6570\u4f4d\u7f6e\u7684\u7d22\u5f15\uff0c\u8fd9\u610f\u5473\u7740\u4f60\u901a\u8fc7\u884c\u53f7\u548c\u5217\u53f7\u6765\u63d0\u53d6\u6570\u636e\u3002<\/p>\n<\/p>\n
      # \u63d0\u53d6\u7b2c\u4e00\u884c<\/p>\n
      first_row = df.iloc[0]<\/p>\n
      \u63d0\u53d6\u7b2c\u4e00\u5217<\/strong><\/h2>\n
      first_column = df.iloc[:, 0]<\/p>\n
      \u63d0\u53d6\u7b2c\u4e00\u884c\u548c\u7b2c\u4e8c\u5217<\/strong><\/h2>\n
      first_row_second_column = df.iloc[0, 1]<\/p>\n
      <\/code><\/pre>\n<\/p>\n
      \u6761\u4ef6\u7b5b\u9009\u6570\u636e<\/strong><\/p>\n<\/p>\n
      Pandas\u5141\u8bb8\u4f60\u901a\u8fc7\u6761\u4ef6\u8bed\u53e5\u5bf9DataFrame\u8fdb\u884c\u7b5b\u9009\u3002\u8fd9\u662f\u4e00\u79cd\u975e\u5e38\u5f3a\u5927\u7684\u6570\u636e\u63d0\u53d6\u65b9\u6cd5\uff0c\u5c24\u5176\u662f\u5728\u5904\u7406\u5927\u89c4\u6a21\u6570\u636e\u96c6\u65f6\u3002<\/p>\n<\/p>\n
      \u4f8b\u5982\uff0c\u5982\u679c\u4f60\u60f3\u7b5b\u9009\u51fa\u5e74\u9f84\u8d85\u8fc730\u7684\u4eba\uff1a<\/p>\n<\/p>\n
      older_than_30 = df[df['Age'] > 30]<\/p>\n
      <\/code><\/pre>\n<\/p>\n
      \u4f60\u4e5f\u53ef\u4ee5\u7ed3\u5408\u591a\u4e2a\u6761\u4ef6\u6765\u8fdb\u884c\u66f4\u590d\u6742\u7684\u7b5b\u9009\uff1a<\/p>\n<\/p>\n
      # \u7b5b\u9009\u51fa\u5e74\u9f84\u5927\u4e8e25\u4e14\u57ce\u5e02\u4e3a'Los Angeles'\u7684\u884c<\/p>\n
      specific_filter = df[(df['Age'] > 25) & (df['City'] == 'Los Angeles')]<\/p>\n
      <\/code><\/pre>\n<\/p>\n
      \u5229\u7528query()\u51fd\u6570\u8fdb\u884c\u67e5\u8be2<\/strong><\/p>\n<\/p>\n
      Pandas\u7684query()\u51fd\u6570\u63d0\u4f9b\u4e86\u4e00\u79cd\u4f7f\u7528\u5b57\u7b26\u4e32\u8868\u8fbe\u5f0f\u7b5b\u9009\u6570\u636e\u7684\u65b9\u5f0f\uff0c\u4f7f\u4ee3\u7801\u66f4\u52a0\u7b80\u6d01\u548c\u6613\u8bfb\u3002<\/p>\n<\/p>\n
      # \u4f7f\u7528query()\u7b5b\u9009\u51fa\u5e74\u9f84\u5927\u4e8e30\u7684\u4eba<\/p>\n
      older_than_30_query = df.query('Age > 30')<\/p>\n
      \u4f7f\u7528query()\u7ed3\u5408\u591a\u4e2a\u6761\u4ef6<\/strong><\/h2>\n
      specific_filter_query = df.query('Age > 25 & City == "Los Angeles"')<\/p>\n
      <\/code><\/pre>\n<\/p>\n
      \u5b57\u7b26\u4e32\u65b9\u6cd5\u63d0\u53d6\u7279\u5b9a\u4fe1\u606f<\/strong><\/p>\n<\/p>\n
      Pandas\u63d0\u4f9b\u4e86\u4e00\u7cfb\u5217\u5b57\u7b26\u4e32\u5904\u7406\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5bf9DataFrame\u4e2d\u7684\u5b57\u7b26\u4e32\u5217\u8fdb\u884c\u64cd\u4f5c\u548c\u63d0\u53d6\u3002<\/p>\n<\/p>\n
      \u5047\u8bbe\u6211\u4eec\u60f3\u4eceCity\u5217\u4e2d\u63d0\u53d6\u4ee5'N'\u5f00\u5934\u7684\u57ce\u5e02\uff1a<\/p>\n<\/p>\n
      cities_starting_with_n = df[df['City'].str.startswith('N')]<\/p>\n
      <\/code><\/pre>\n<\/p>\n
      \u4f60\u8fd8\u53ef\u4ee5\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u8fdb\u884c\u66f4\u590d\u6742\u7684\u5b57\u7b26\u4e32\u5339\u914d\uff1a<\/p>\n<\/p>\n
      import re<\/p>\n
      \u63d0\u53d6\u57ce\u5e02\u540d\u4e2d\u5305\u542b'o'\u7684\u884c<\/strong><\/h2>\n
      cities_with_o = df[df['City'].str.contAI<\/a>ns('o', flags=re.IGNORECASE)]<\/p>\n
      <\/code><\/pre>\n<\/p>\n
      \u603b\u7ed3<\/strong><\/p>\n<\/p>\n
      Pandas\u63d0\u4f9b\u4e86\u591a\u79cd\u65b9\u6cd5\u6765\u63d0\u53d6\u6570\u636e\uff0c\u6bcf\u79cd\u65b9\u6cd5\u90fd\u6709\u5176\u7279\u5b9a\u7684\u5e94\u7528\u573a\u666f\u548c\u4f18\u70b9\u3002\u901a\u8fc7.loc[]\u548c.iloc[]\u53ef\u4ee5\u6839\u636e\u6807\u7b7e\u6216\u4f4d\u7f6e\u63d0\u53d6\u6570\u636e\uff0c\u5229\u7528\u6761\u4ef6\u7b5b\u9009\u548cquery()\u51fd\u6570\u53ef\u4ee5\u5b9e\u73b0\u590d\u6742\u7684\u6570\u636e\u67e5\u8be2\uff0c\u5b57\u7b26\u4e32\u65b9\u6cd5\u5219\u63d0\u4f9b\u4e86\u7075\u6d3b\u7684\u6587\u672c\u5904\u7406\u529f\u80fd\u3002\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u53d6\u51b3\u4e8e\u5177\u4f53\u7684\u6570\u636e\u7ed3\u6784\u548c\u63d0\u53d6\u9700\u6c42\u3002\u65e0\u8bba\u662f\u5bf9\u521d\u5b66\u8005\u8fd8\u662f\u7ecf\u9a8c\u4e30\u5bcc\u7684\u6570\u636e\u5206\u6790\u5e08\uff0c\u8fd9\u4e9b\u65b9\u6cd5\u90fd\u662f\u8fdb\u884c\u6570\u636e\u5206\u6790\u8fc7\u7a0b\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u5de5\u5177\u3002<\/p>\n<\/p>\n
      \u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
       \u5982\u4f55\u4f7f\u7528Python Pandas\u7b5b\u9009\u7279\u5b9a\u6761\u4ef6\u4e0b\u7684\u6570\u636e\uff1f<\/strong>
      \u5728Python Pandas\u4e2d\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528\u5e03\u5c14\u7d22\u5f15\u6765\u7b5b\u9009\u7b26\u5408\u7279\u5b9a\u6761\u4ef6\u7684\u6570\u636e\u3002\u4f8b\u5982\uff0c\u5982\u679c\u60a8\u60f3\u63d0\u53d6\u67d0\u4e00\u5217\u4e2d\u503c\u5927\u4e8e\u7279\u5b9a\u6570\u5b57\u7684\u884c\uff0c\u53ef\u4ee5\u4f7f\u7528\u7c7b\u4f3c\u4ee5\u4e0b\u7684\u4ee3\u7801\uff1adf[df['\u5217\u540d'] > \u6570\u5b57]<\/code>\u3002\u8fd9\u6837\uff0c\u60a8\u5c06\u83b7\u5f97\u4e00\u4e2a\u65b0\u7684\u6570\u636e\u6846\uff0c\u5176\u4e2d\u4ec5\u5305\u542b\u7b26\u5408\u6761\u4ef6\u7684\u884c\u3002\u60a8\u8fd8\u53ef\u4ee5\u7ed3\u5408\u591a\u4e2a\u6761\u4ef6\uff0c\u4f7f\u7528&<\/code>\uff08\u4e0e\uff09\u6216|<\/code>\uff08\u6216\uff09\u64cd\u4f5c\u7b26\u8fdb\u884c\u66f4\u590d\u6742\u7684\u7b5b\u9009\u3002<\/p>\n
      Pandas\u4e2d\u5982\u4f55\u63d0\u53d6\u7279\u5b9a\u5217\u7684\u6570\u636e\uff1f<\/strong>
      \u5982\u679c\u60a8\u53ea\u60f3\u63d0\u53d6\u6570\u636e\u6846\u4e2d\u7684\u67d0\u51e0\u5217\uff0c\u53ef\u4ee5\u901a\u8fc7\u5217\u540d\u5217\u8868\u8f7b\u677e\u5b9e\u73b0\u3002\u4f7f\u7528df[['\u5217\u540d1', '\u5217\u540d2']]<\/code>\u7684\u65b9\u5f0f\uff0c\u60a8\u5c06\u83b7\u5f97\u4e00\u4e2a\u65b0\u7684\u6570\u636e\u6846\uff0c\u4ec5\u5305\u542b\u6307\u5b9a\u7684\u5217\u3002\u6b64\u5916\uff0c\u8fd8\u53ef\u4ee5\u901a\u8fc7df.loc[:, '\u5217\u540d']<\/code>\u7684\u65b9\u5f0f\u63d0\u53d6\u7279\u5b9a\u7684\u5217\u3002<\/p>\n
      \u5982\u4f55\u4ecePandas DataFrame\u4e2d\u63d0\u53d6\u7f3a\u5931\u503c\uff1f<\/strong>
      \u5728\u5904\u7406\u6570\u636e\u65f6\uff0c\u60a8\u53ef\u80fd\u4f1a\u9047\u5230\u7f3a\u5931\u503c\u3002\u8981\u63d0\u53d6\u542b\u6709\u7f3a\u5931\u503c\u7684\u884c\uff0c\u53ef\u4ee5\u4f7f\u7528df[df['\u5217\u540d'].isnull()]<\/code>\uff0c\u8fd9\u5c06\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u6570\u636e\u6846\uff0c\u5305\u542b\u5728\u6307\u5b9a\u5217\u4e2d\u6709\u7f3a\u5931\u503c\u7684\u6240\u6709\u884c\u3002\u5982\u679c\u60a8\u5e0c\u671b\u63d0\u53d6\u6ca1\u6709\u7f3a\u5931\u503c\u7684\u884c\uff0c\u53ef\u4ee5\u4f7f\u7528df[df['\u5217\u540d'].notnull()]<\/code>\u3002\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\uff0c\u60a8\u53ef\u4ee5\u6709\u6548\u5730\u6e05\u7406\u548c\u5206\u6790\u6570\u636e\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u4f7f\u7528Python Pandas\u63d0\u53d6\u6570\u636e\u7684\u6838\u5fc3\u65b9\u6cd5\u5305\u62ec\uff1a\u4f7f\u7528.loc[]\u548c.iloc[]\u8fdb\u884c\u7d22\u5f15\u3001\u4f7f\u7528\u6761\u4ef6\u7b5b\u9009\u6570 […]","protected":false},"author":3,"featured_media":991172,"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\/991165"}],"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=991165"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/991165\/revisions"}],"predecessor-version":[{"id":991175,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/991165\/revisions\/991175"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/991172"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=991165"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=991165"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=991165"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}