Semaphore class in threading module implements semaphore object, which can be used to control the number of threads obtaining resources. The acquire() and release() methods can be used as the context manager of the with statement. The acquire() method is called when entering, and release() is called when exiting.
Semaphore is simila ...
Posted by cemeteryridge on Sun, 09 Jan 2022 17:46:44 +0100
This article mainly introduces the detailed explanation of Python function definition and parameter transmission methods (4 kinds). The example code in this article is very detailed, which has certain reference and learning value for everyone's study or work. Friends in need, let's learn together with Xiaobian
1, Elementary knowledge of functi ...
Posted by Urbley on Sun, 09 Jan 2022 17:42:56 +0100
Semaphores, in other words, control the number of concurrent threads, which is the number of concurrent threads in turn
See the example:
import threading # Import module
import time # Import module
class Exam(threading.Thread): # Create class
def __init__(self, num): # initialization
super(Exam, self).__init__() # Parent cl ...
Posted by elabuwa on Sun, 09 Jan 2022 17:33:50 +0100
k elements are randomly selected from D as the respective centers of k clusters;Calculate the dissimilarity of the remaining elements to the center of k clusters, and classify these elements into the cluster with the lowest dissimilarity;According to the clustering results, the respective centers of k clusters are ...
Posted by joel danny on Sun, 09 Jan 2022 16:43:55 +0100
In the web crawler, some websites will set anti crawler measures. The server will detect the number of requests of an IP in unit time. If it exceeds this threshold, it will directly refuse service and return some error messages, such as 403 Forbidden, "your IP access frequency is too high", which means that the IP is blocked ...
Posted by spectacularstuff on Sun, 09 Jan 2022 15:52:29 +0100
I. contour detection Although edge detection can detect edges, its edges are not continuous. The image contour is used to detect a whole for subsequent processing. opencv provides two functions to complete these operations: findContours(): this function can find contours drawContours(): draw contours The difference between contour and edge is t ...
Posted by theslug on Sun, 09 Jan 2022 13:22:12 +0100
The content of this article comes from learning MIT open course: univariate calculus - correlation rate - Netease open course
1, Examples of best value problems
1. Cut a line with a length of 1 into 2 segments, circle each segment into a square, and find the maximum area that can be obtained
Calculate both ends:
Therefore, when t ...
Posted by yasir_memon on Sun, 09 Jan 2022 12:25:35 +0100
Classification method based on probability theory: Naive Bayes
Advantages: it is still effective in the case of less data (but the accuracy is also inexhaustible), and can deal with multi category problems.
Disadvantages: it is sensitive to the way data is input.
Applicable data type: nominal data.
Pre knowledge: conditional probability, Bay ...
I finally finished my final homework, I can't catch me (No. last time I talked about solving linear equations by LU decomposition, but sometimes when the equations are incompatible, the conventional method will fail. At this time, we can use the least square method. Of course, for matrix fitting, we can directly calculate th ...
Posted by mo0ness on Sun, 09 Jan 2022 09:46:41 +0100
This note is used to explain in detail how to convert classes in c + + into classes that can be used directly in the python environment.
A simple c + + class RealWorld is defined here, including public, private members and public member functions. In this example, we will show how to convert the member functions an ...
Posted by anna_cm on Sun, 09 Jan 2022 09:32:05 +0100