Tag:empty

  • List foundation of Python

    Time:2022-5-2

    ”’List: there are all types of data, and different types of data can be storedCan be accessed by subscript. Subscript starts at 0 ”’ List creation list_1 = [1,2,3,’4′] list_2 = list() ergodic for i in list_1: print(i, end=’ ‘) print(” “) Get list data according to subscript value = list_1[-1] #Print (‘last element:% s’% […]

  • Vue router emptying history

    Time:2022-4-27

    Problem description When we browse multiple pages, the token expires. At this time, the system should force the user to log out. Although the user logs out, if the previous browsing history is not cleared, click the return button of the browser, and the browser will still return to the previous page. When the number […]

  • How to greatly reduce the storage time of Seurat object, the size of Seurat object and the size of Seurat matrix

    Time:2022-4-25

    How to greatly reduce the storage time of Seurat objects Seurat R package is undoubtedly one of the longest used packages for single cell analysis. During Seurat analysis, the results of each step are stored in different slots of Seurat objects. The advantage is that all the calculated information can be retained. However, at the […]

  • ES6 must know, look! (2)

    Time:2022-4-25

    Part 1 class Features: it is declared with class, which is essentially function, and the class name is suggested to start with uppercaseIn order to learn better, you should first master the following words: Constructor constructor Super super Extensions inheritance New instantiation example: class Cat extends Animal{ constructor(name,color){ super(name); this.color = color; } say(){} } […]

  • Copy plate to clipping plate

    Time:2022-4-23

    #coding:utf-8 import win32clipboard as clip import win32con from PIL import Image from cStringIO import StringIO ”’ Put a picture on the clipboard ”’ def setImage(data): clip. Openclipboard() # opens the clipboard clip. Emptyclipboard() # empty the clipboard first clip. Setclipboarddata (win32con. Cf_dib, data) # put the picture on the clipboard clip.CloseClipboard() if __name__ == ‘__main__’: […]

  • Tips for shell script to calculate the length of string and judge whether the string is empty

    Time:2022-4-17

    Some script problems needing attention There are three ways to calculate the length of a string: Copy codeThe code is as follows: echo “$str”|awk ‘{print length($0)}’ expr length “$str” echo “$str”|wc -c However, the value of the third type will be 1 more, which may include the terminator There are three ways to judge whether […]

  • Force cleaning and refreshing browser cache

    Time:2022-4-16

    Today, I encountered a problem. The online system page Jump is abnormal, but only my exception. Other colleagues are normal. The first thing I think of is to clean up the browser cache!!! I usually clean the browser cache myself,Developer tools (F12) – > Application – > storage – > clear site dataBasically, it can […]

  • The processing of electronic signature is adopted in the front-end project Vue & element project based on ABP framework

    Time:2022-4-15

    In the previous essay, I introduced《In the front-end project Vue & element project based on ABP framework, electronic signature is used to process documents and print》Sometimes, we need to sign our own name in the process or when signing some documents. Generally, we realize the processing of electronic signature by means of signature form (very […]

  • IO multiplexing from the perspective of go programming

    Time:2022-4-8

    IO multiplexing enables the process to listen to some file descriptors through some mechanism. When there are read or write ready in the file descriptor, the process can receive the corresponding notification sent by the system kernel to carry out the corresponding IO operation; IO multiplexing includes: select, poll, epoll and other modes. Here we […]

  • JS implements the input box that can be cleared in element (2)

    Time:2022-4-3

    Then, in the previous article: JS implements the emptiable input box in element (1) and continues to optimize. If you are interested, you can have a look. Through train link: https://www.cnblogs.com/qcq0703/p/14450001.html The implementation effect is shown in the figure below: https://element.eleme.cn/#/zh -CN/component/input First, describe the shape of this input box 1. Border fillet 2. Emptying […]

  • C + + speech contest process management system

    Time:2022-3-30

    catalogue Speech contest process management system 1、 Program requirements 1. Competition rules 2. Program function 2、 Create management class 1. Create file 2. Header file implementation 3. Source file implementation 3、 Menu function 1. Add member function 2. Implementation function 3. Test function 4、 Exit function 1. Provide functional interface 2. Add member function 3. […]

  • Linux empties file contents

    Time:2022-3-25

    VI “% d” command emptying, slow processing when the file is large VI {file} Enter:% D and execute enter Enter: WQ enter save and exit Cat command implementation Cat / dev / null > {file} The echo command is not completely empty, and an empty line “\ n” will be written to the file Echo […]