was originally intended to use redis s HyperLogLog for statistics, but since users only have one chance to like each article, it is impossible to keep playing redis to determine whether users have liked it or not. But the efficiency of using mysql is to...
there is a sample, column an is the number, column b is the number of occurrence of the number, the sample is very large, the standard deviation and normal distribution map of this sample is required, how should we deal with it with python? I ve checked...
city id name 1 Beijing 2 Shanghai 3 Tianjin news Newslist id name city 1 my 1 2 my 2 3 my 2 4 my 3 find out how many messages are there in Beijing how many messages are there in Shanghai how many messages are there in Tianjin ...
Reading websites often have today s page views, today s posts, today s comments and so on. Which statistical scheme is better? file + Cookie mode, the file on the server is emptied once in 24 hours. the dat file is accessed only once by the client...
recently, we are going to do a statistics on the activity of the industry in the project, and the three factors that affect the activity of the industry are the number of posts issued by the industry, the number of comments on the information of the indu...
for example: has a table in which two columns, title and provenance, are set with unique properties demand: ,, attempt operation: when inserting using the following sql statement, it is found that only one piece of data can be inserted. Limited b...
echarts horizontal and vertical coordinate points can be set gridlines, but if the coordinate points are relatively few and the width and height of the echarts instance is relatively large, the single grid will be very large and the style is not very be...
I used paging crawlers with the same structure for three websites. But the result of two of the crawlers is to collect only one piece of data per page, and then start to turn the page until the last page and then go back to collect other data from the pr...
beginner to learn the algorithm, do not quite understand the concept of this block, such as a function function fn(){ for(i = 0; i < n; iPP){} } if this is the case, how to calculate the time complexity? is it O (nlogn+n), or can it no...
the way to introduce flash into the electron official website is realized by introducing pulgins into the webview tag, but I want to integrate flash locally, that is, to play a swf video in the index.html in the electron project. Can you give me some adv...