漫步量化

Overview使用requests发送消息，出现如下错误：Can’t connect to HTTPS URL because the SSL module is not available.请求的url并无问题，Linux端的运行也正常，只有Windows下面anaconda运行异常。Solution参考中3，4，5是比较常见的几种解释，于我情况无作用。我的情况是采用Reference1中第二个答案：# copy the fileslibcrypto-1_1-x64.*li..

OverviewTo convert this question into english, maybe:How to convert a DataFrame into a petty HTML table and send it over Email, like this one here.From R1,there is a module named pretty_html_table .pretty_html_tableThe objective of this package is..

full-duplexA full-duplex(FDX) system, or somethings called double-duplex(HDX), allows communication in both directions, and unlike half-duplex, allows this to happen simultaneously.IETFThe Internet Engineering Task Force (IETF) is a large open inter..

endpoint《理解endpoint vs API 》signed《理解signature on API Requests》《理解digital signatures vs MAC on cryptography》You can take signed endpoint simply as the endpoint which need a signature param.

signature关于signature 参见《理解digital signatures vs MAC on cryptography》signature on APIsignature 与API在一起，指请求api地址的时候，将signature作为一个参数加到query字段中。比如(伪代码)：# 原query字段querystring="stock=000001&type=sh"# 第一步：将query字段与encryption key放在一起计算macmac=macAl..

OverviewGenerally speaking, Document-Centric and Data-Centric are two broad applications areas of XML technologies.Document Centric XMLDocument Centric(document-oriented) uses XML to impose structure on information that rarely fits into a relational..

robots.txtrobos.txtRobots.txt 规范The robots exclusion standard, also known as the robots exclusion protocol or simply robots.txt, is a standard used by websites to communicate with web crawlers and other web robots.The standard specifies how to info..

endpointApplication Programm Interface (API) permits the interaction between two systems.In simple terms, an API endpoint is the point entry in a communication channel when two systems are interacting.It refers to touchpoints of the communication betw..

URLA URL (Uniform Resource Locator), more commonly known as a “web address”, specifies the location of a resource (such as a web page) on the internet.The URL also specifies how to retrieve that resource, also known as the “Protocol”, such as HTTP, HTT..

问题描述爬虫任务中，所需内容在:<table class="table_search_"> <tbody> <tr>...</tr> <tr>...</tr> <tr>...</tr>可以定位到table class="table_search_"，但是没有想要的内容。即，无法提取tbody内容。问题解析[爬虫]xpath无法定位tbo..

XMLExtensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable.The design goals of XML emphasize simplictiy, generality, and usability across the ..

OverviewhomepagePython 爬虫利器三之 Xpath 语法与 lxml 库的用法The ElementTree XML API in PythonThe lxml XML toolkit is a Pythonic binding for the C libraries libxml2 and libxslt. It is unique in that it combines the speed and XML feature completeness of these l..

缘起用Python写爬虫，对于AJAX内容，需要在request.get(url, headers)中传入headers,需要了解headers中各项的意义。Request header 请求头HTTP header fields are components of the header section of request and response messages in the Hypertext Transfer Protocol (HTTP). They define the oper..

问题描述websocket方式连接Sanic服务器，经常断开连接。解决方案aiohttp throws CancelledError into coroutine if http connection was disconnected.1这个问题本源在于websocket连接断开了，在本例中因为websocket server是每隔几分钟推送有一次数据，时间间隔太长导致连接断开。进而导致如下错误：websockets.exceptions.ConnectionClosedError: co..

问题描述将websocket的on_open()封装到一个类中，就会出现如题问题。解决方案问题出在websocket的_callback方法调用上。 def _callback(self, callback, *args): if callback: try: if inspect.ismethod(ca...

HTTP：HyperText Transfer Protocol，超文本传输协议，菜鸟教程是一种无状态的请求/响应的网络传输协议。基于TCP/IP通信协议（通过一个可靠的链接）传递数据。HTTP协议工作于客户端-服务端架构。HTTP客户端（浏览器）通过URL向HTTP服务端（WEB服务器）发送请求。默认端口号80.HTTP无连接、媒体独立、无状态。CGI Program(Wiki...

控制帧控制帧用于WebSocket协议交换状态信息，控制帧可以插在消息片段之间。所有的控制帧的负载长度均不大于125字节，并且禁止对控制帧进行分片处理。目前控制帧的操作码定义了oxo8(关闭帧)、oxo9(Ping帧)、oxoA(Pong帧)。关闭帧（oxo8）关闭帧可能包含数据部分，该部分表名了关闭的原因。客户端发送给服务器的关闭帧必须掩码处理。应用程序在发送了一个关闭帧后...

问题描述websocket 服务端爆出如上问题。解决方案问题的出现是由于在async def定义的函数内部使用了loop=asyncio.get_event_loop()，需要将事件循环提取到async def函数外面ReferencesLearning asyncio: “coroutine was never awaited” warning errorCommo...

问题描述class Something(): def on_message(self,ws, message): pass ... def main(self): websocket.enableTrace(True) ws = websocket.WebSocketApp("wss://stream.b...

线程和进程线程、进程经常放在一起对比：《线程||进程||行程||多线程||多进程一次搞清》《IO密集型任务（多线程）||计算密集型（多进程）》线程是最小单位，进程内至少包含一个线程。对操作系统来说，线程是最小的执行单元，进程是最小的资源管理单元。进程间的切换（涉及栈、寄存器、虚拟内存、文件句柄等）开销较大，但是相对安全；不同进程通过进程间通讯来通信。线程是比进程更小的、CPU调度...

并发/并行从物理基础元素角度来看，当只有一个CPU时，执行一个程序这个程序就会一直占用CPU，直到程序运行结束。如果这个程序的运行过程中，需要用到CPU的部分很快就结束了，程序的其他环节（比如IO阻塞等）正在占用时间，此时CPU是空置的。于是就有了并发。并发的不足并发执行加速了对CPU的使用效率，也带来了问题。程序A运行到一半，程序B进来抢占CPU，程序A的中间状态/内存/变量...

HTTP包体HTTP是一个客户端（用户）和服务端（网站）之间请求和应答的标准，通常使用TCP协议。通过使用网页浏览器、网络爬虫或者其它的工具，客户端发起一个HTTP请求到服务器上指定端口（默认端口为80）。我们称这个客户端为用户代理程序（user agent）。应答的服务器上存储着一些资源，比如HTML文件和图像。我们称这个应答服务器为源服务器（origin server）。在用户代理...