• Teach you time travel under Linux


    Time travel? The bridge in the movie? Liangxu, are you bluffing again? No, No. Liang Xu wants to introduce the touch command here. With it, you can change the timestamp to achieve the purpose of time travel. The touch command is also used quite frequently in our work. We will explain it in detail from […]

  • Specific use of NP. Where() [0] and NP. Where() [1]


    This paper mainly introduces the specific use of NP. Where() [0] and NP. Where() [1], as well as the specific usage of NP. Where(). There is no more nonsense, as follows: ? 1 2 3 4 5 6 7 8 9 import numpy as np   a = np.arange(12).reshape(3,4) print(‘a:’, a) print(‘np.where(a > 5):’, np.where(a […]

  • Django information (will be updated continuously)


    Request and response in Django The in-depth technical comparison between rails and Django is difficult to choose Advanced usage of Django template

  • Webpack first experience


    Webpack basic usage Entry of core concepts Entry is used to specify the packaging entry of the webpack. Webpack is a module packer. In webpack, all resources (JS, CSS, HTML, pictures and fonts) will be regarded as modules. All these modules will have dependencies before. Therefore, webpack will start to look for dependencies from the […]

  • Daily soul question – how to monitor and optimize node performance?


    1、 Node performance index: 1. CPU (synchronous will occupy, asynchronous will not) CPU loadCPU utilization 2. Memory In the node, the maximum memory capacity of a process is 1.5GB. Therefore, we need to reduce memory leakage //RSS represents the total amount of memory occupied by the node process //Heaptotal: indicates the total amount of heap […]

  • Fetch API


    Fetch API One of the deepest secrets is the underlying of Ajax implementationXMLHttpRequest, this method was not made to do this. There are many elegant API wrappers for XHR, but that’s not enough. So there wasfetchAPI。 Let’s take a look at the basic usage of this API. The latest browsers already support this method. XMLHttpRequest […]

  • Python tutorial: three very useful built-in functions (filter / map / reduce)


    These three built-in functions are still very useful. They are still used in work. They are easy to use. Let’s introduce them one by one 1、filter Syntax:filter(function,iterable) Explanation: filter out the desired data through the function function of the iterator Usage: you can set an iterator and filter out elements with the same attribute, as […]

  • Conversion between c# datetime and timestamp


    The usage is very simple. Pass in the current time (e.gDateTime.Now)Or 10 bit timestamp (1590491120): using System; //Datetime to timestamp long UnixTimestamp(DateTime dateTime) { DateTime dt1970 = new DateTime(1970, 1, 1, 0, 0, 0, 0); return (dateTime.Ticks – dt1970.Ticks) / 10000000; } //Timestamp to datetime DateTime GetDateTimeFrom1970Ticks(long curSeconds) { DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, […]

  • How to dynamically generate form in Vue


    Form create is a form generation component that can generate dynamic rendering, data collection, verification and submission through JSON. It supports 3 UI frameworks and supports the generation of any Vue component. Built in 20 kinds of common form components and custom components, even complex forms can be easily handled. file | GitHub Support UI […]

  • Do a good job of automated API testing (1) – start with a useful JSON validator


    At present, the development mode of separating the front end and the back end is more and more popular, and the responsibilities of the front end and the back end are clearer. The back end provides data through API, and the front end obtains data and displays pages through API. The front end has more […]

  • Lodash common API notes


    At present, I only found version 3.10. X of lodash Chinese documents. Now lodash has been updated to 4.17. X, and many documents have expired. Moreover, there are too many APIs in lodash. Sometimes I can’t remember the names of the commonly used ones. Post them here to facilitate myself and everyone. Native usage API […]

  • File operation with Python


    What is a file A file is a named location in the storage area of the system, which is used to store some information for subsequent access. It can realize continuous storage in nonvolatile memory, such as on hard disk. When we want to read or write a file, we need to open the file; […]