{"id":2229,"date":"2021-08-03T20:58:37","date_gmt":"2021-08-03T12:58:37","guid":{"rendered":"https:\/\/egonlin.com\/?p=2229"},"modified":"2022-02-07T10:30:08","modified_gmt":"2022-02-07T02:30:08","slug":"%e7%ac%ac%e4%b8%80%e8%8a%82%ef%bc%9aflask%e9%ab%98%e7%ba%a7","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=2229","title":{"rendered":"\u7b2c\u4e00\u8282\uff1aflask\u9ad8\u7ea7"},"content":{"rendered":"

08-Flask\u9ad8\u7ea7<\/h1>\n

01 \u8bf7\u6c42\u6269\u5c55<\/h1>\n

01 before_first_request \uff1a\u9879\u76ee\u542f\u52a8\u540e\u7b2c\u4e00\u6b21\u8bf7\u6c42\u7684\u65f6\u5019\u6267\u884c<\/h3>\n
@app.before_first_request\ndef before_first_request():\n    print('\u7b2c\u4e00\u6b21\u8bf7\u6c42\u7684\u65f6\u5019\u6267\u884c')<\/code><\/pre>\n
02  before_request\uff1a\u6bcf\u6b21\u8bf7\u6c42\u4e4b\u524d\u6267\u884c<\/h3>\n
@app.before_request\ndef before_request():\n    print('\u6bcf\u6b21\u8bf7\u6c42\u4e4b\u524d\u6267\u884c')\n    # return '\u76f4\u63a5return'    # \u5982\u679c\u6709\u4e00\u4e2a\u5199\u4e86return\u8fd4\u56de\u503c\uff0c\u90a3\u4e48\u5176\u4ed6\u7684before_request\u4e0d\u4f1a\u6267\u884c\uff0c\u89c6\u56fe\u4e5f\u4e0d\u4f1a\u6267\u884c\u3002<\/code><\/pre>\n
\u6ce8\u610f\uff1a<\/strong><\/p>\n
    \n
  • \n
    \u53ef\u4ee5\u5199\u591a\u4e2a<\/p>\n<\/li>\n
  • \n
    \u5982\u679c\u6709\u4e00\u4e2a\u5199\u4e86return\u8fd4\u56de\u503c\uff0c\u90a3\u4e48\u5176\u4ed6\u7684before_request\u4e0d\u4f1a\u6267\u884c\uff0c\u89c6\u56fe\u4e5f\u4e0d\u4f1a\u6267\u884c\u3002<\/p>\n<\/li>\n<\/ul>\n
    03  after_request\uff1a\u6bcf\u6b21\u8bf7\u6c42\u4e4b\u540e\u6267\u884c\uff0c\u8bf7\u6c42\u51fa\u73b0\u5f02\u5e38\u4e0d\u4f1a\u6267\u884c<\/h3>\n
    def after_request(result):\n    print('\u6bcf\u6b21\u8bf7\u6c42\u4e4b\u540e\u6267\u884c\uff0c\u8bf7\u6c42\u51fa\u73b0\u5f02\u5e38\u4e0d\u4f1a\u6267\u884c')\n    # \u8fd9\u4e2aresult\u662f\u5c01\u88c5\u7684\u54cd\u5e94\u5bf9\u8c61\uff0c\u9700\u8981return\u5426\u5219\u62a5\u9519\n    return result<\/code><\/pre>\n
    04  errorhandler\uff1a\u53ef\u4ee5\u81ea\u5b9a\u4e49\u76d1\u542c\u54cd\u5e94\u7684\u72b6\u6001\u7801\u5e76\u5904\u7406\uff1a<\/h3>\n
    @app.errorhandler(404)\ndef errorhandler(error):\n    print(error)  # \u662f\u5177\u4f53\u7684\u9519\u8bef\u4fe1\u606f\n    return '404\u9875\u9762\u8dd1\u5230\u4e86\u706b\u661f\u4e0a\u9762\u53bb\u4e86'\n\n@app.errorhandler(500)\ndef errorhandler(error):\n    print('errorhandler\u7684\u9519\u8bef\u4fe1\u606f')\n    print(error)\n    return '\u670d\u52a1\u5668\u5185\u90e8\u9519\u8bef500'<\/code><\/pre>\n
    05  teardown_request\uff1a\u6bcf\u6b21\u8bf7\u6c42\u4e4b\u540e\u7ed1\u5b9a\u4e86\u4e00\u4e2a\u51fd\u6570\uff0c\u5728\u975edebug<\/code>\u6a21\u5f0f\u4e0b\u5373\u4f7f\u9047\u5230\u4e86\u5f02\u5e38\u4e5f\u4f1a\u6267\u884c\u3002<\/h3>\n
    @app.teardown_request\ndef terardown_reqquest(error):\n    print('\u65e0\u8bba\u89c6\u56fe\u51fd\u6570\u662f\u5426\u6709\u9519\u8bef\uff0c\u89c6\u56fe\u51fd\u6570\u6267\u884c\u5b8c\u90fd\u4f1a\u6267\u884c')\n    print('\u60f3\u8981\u6b64\u51fd\u6570\u751f\u6548\uff0cdebug\u4e0d\u80fd\u4e3aTrue')\n    print('error \u662f\u5177\u4f53\u7684\u9519\u8bef\u4fe1\u606f')\n    print(error)<\/code><\/pre>\n
    06  template_global()\uff1a\u5168\u5c40\u6a21\u677f\u6807\u7b7e<\/h3>\n
    @app.template_global()\ndef add(a1, a2):\n    return a1+a2\n#{{add(1,2)}}<\/code><\/pre>\n
    \u8fd9\u4e2a\u53ef\u4ee5\u5728\u6a21\u677f\u4e2d\u4f5c\u4e3a\u5168\u5c40\u7684\u6807\u7b7e\u4f7f\u7528,\u5728\u6a21\u677f\u4e2d\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\uff0c\u8c03\u7528\u65b9\u5f0f\uff1a<\/p>\n
    {{add(1,2)}}<\/code><\/pre>\n
    07 template_filter\uff1a\u5168\u5c40\u6a21\u677f\u8fc7\u6ee4\u5668<\/h3>\n
    @app.template_filter()\ndef add_filter(a1, a2, a3):\n    return a1 + a2 + a3<\/code><\/pre>\n
    \u8fd9\u4e2a\u53ef\u4ee5\u5728\u6a21\u677f\u4e2d\u4f5c\u4e3a\u5168\u5c40\u8fc7\u6ee4\u5668\u4f7f\u7528\uff0c\u5728\u6a21\u677f\u4e2d\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\uff0c\u8c03\u7528\u65b9\u5f0f(\u6ce8\u610f\u540ctemplate_global\u7684\u533a\u522b<\/em>) \uff1a<\/p>\n
    {{1|add_filter(2,3,4)}}<\/code><\/pre>\n
    \u4f18\u52bf\uff1a<\/strong><\/p>\n
    \u5168\u5c40\u6a21\u677f\u6807\u7b7e\u548c\u5168\u5c40\u6a21\u677f\u8fc7\u6ee4\u5668\u7b80\u5316\u4e86\u9700\u8981\u624b\u52a8\u4f20\u4e00\u4e2a\u51fd\u6570\u7ed9\u6a21\u677f\u8c03\u7528\uff1a<\/p>\n
    # app.py\n```\n\ndef test(a1,a2):\n    return a1+a2\n@app.route(&#039;\/&#039;)\ndef index():\n    return render_template(&#039;index.html&#039;,test=test)\n\n```\n\n# index.html\n```\n{{test(22,22)}}\n\n```\n<\/code><\/pre>\n
    02    flask\u4e2d\u95f4\u4ef6<\/h1>\n
    Flask\u7684\u4e2d\u95f4\u4ef6\u7684\u6027\u8d28\uff0c\u5c31\u662f\u53ef\u4ee5\u7406\u89e3\u4e3a\u5728\u6574\u4e2a\u8bf7\u6c42\u7684\u8fc7\u7a0b\u7684\u524d\u540e\u5b9a\u5236\u4e00\u4e9b\u4e2a\u6027\u5316\u7684\u529f\u80fd\u3002<\/p>\n
    flask\u7684\u4e2d\u95f4\u4ef6\u7684\u5b9e\u73b0\u6848\u4f8b\uff1a<\/h5>\n
    from flask import Flask\n\napp = Flask(__name__)\n\n@app.route('\/')\ndef index():\n    print('\u89c6\u56fe\u51fd\u6570\u4e2d')\n    return 'hello world'\n\nclass my_middle:\n\n    def __init__(self,wsgi_app):\n        self.wsgi_app = wsgi_app\n\n    def __call__(self, *args, **kwargs):\n        print('\u4e2d\u95f4\u4ef6\u7684\u4ee3\u7801\u4e0a')\n        obj = self.wsgi_app( *args, **kwargs)\n        print('\u4e2d\u95f4\u4ef6\u7684\u4ee3\u7801\u4e0b')\n\n        return obj\n\nif __name__ == '__main__':\n\n    app.wsgi_app = my_middle(app.wsgi_app)\n     # app.wsgi_app(environ, start_response)\n    app.run()\n    # \u68b3\u7406\u4e00\u4e0b \u6839\u636ewerkzeug\u6211\u4eec\u53ef\u4ee5\u77e5\u9053 \u6bcf\u6b21\u8bf7\u6c42\u5fc5\u7136\u7ecf\u5386\u4e86app\uff08\uff09\n    # \u6240\u4ee5\u6211\u4eec\u8981\u67e5\u770bFlask\u7684\u6e90\u7801\u627e\u5230__call__\u65b9\u6cd5\n    # \u627e\u5230\u4e86__call__\u65b9\u6cd5\u540e\u53d1\u73b0\u6267\u884c\u4e86return self.wsgi_app(environ, start_response)\n    # \u7136\u540eflask\u91cc\u9762\u6240\u6709\u7684\u5185\u5bb9\u8c03\u5ea6\u90fd\u662f\u57fa\u4e8e\u8fd9\u4e2aself.wsgi_app(environ, start_response)\uff0c\u8fd9\u5c31\u662f\u5c31\u662fflask\u7684\u5165\u53e3\n    # \u5982\u4f55\u5b9e\u73b0\u4e2d\u95f4\u4ef6\u5462\uff1f \u539f\u7406\u4e0a\u5c31\u662f\u91cd\u5199app.wsgi_app\uff0c\u7136\u540e\u5728\u91cc\u9762\u6dfb\u52a0\u4e0a\u4e00\u4e9b\u81ea\u5df1\u60f3\u8981\u5b9e\u73b0\u7684\u529f\u80fd\u3002\n    # \u9996\u5148\u5206\u6790  app.wsgi_app\u9700\u8981\u52a0\u62ec\u53f7\u6267\u884c  \u6240\u4ee5\u6211\u4eec\u628aapp.wsgi_app\u505a\u6210\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5e76\u4e14\u8fd9\u4e2a\u5bf9\u8c61\u9700\u8981\u52a0\u62ec\u53f7\u8fd0\u884c\n    # \u4e5f\u5c31\u662f\u4f1a\u89e6\u53d1\u8fd9\u4e2a\u5bf9\u8c61\u7684\u7c7b\u7684__call__()\u65b9\u6cd5\n    # 1 \u90a3\u4e48\u5c31\u662fapp.wsgi_app=\u5bf9\u8c61=\u81ea\u5df1\u91cd\u5199\u7684\u7c7b(app.wsgi_app) \uff0c\u6211\u4eec\u9700\u8981\u5728\u81ea\u5df1\u91cd\u5199\u7684\u7c7b\u91cc\u9762\u5b9e\u73b0flask\u6e90\u7801\u4e2d\u7684app.wsgi_app,\u5728\u5b9e\u4f8b\u5316\u7684\u8fc7\u7a0b\u628a\u539f\u6765\u7684app.wsgi_app\u53d8\u6210\u5bf9\u8c61\u7684\u5c5e\u6027\n    # 2         app.wsgi_app() =\u5bf9\u8c61() = \u81ea\u5df1\u91cd\u5199\u7684\u7c7b.call()\u65b9\u6cd5\n    # 3         \u90a3\u4e48\u4e0a\u9762\u7684\u4ee3\u7801\u5c31\u53ef\u4ee5\u7406\u89e3\u4e86\uff0c\u5728\u81ea\u5df1\u91cd\u5199\u7684\u7c7b\u4e2d\u5b9e\u73b0\u4e86\u539f\u6709\u7684__call__\u65b9\u6cd5\n<\/code><\/pre>\n
    \u68b3\u7406\uff1a<\/h5>\n