Opencv visual eye Python image processing Xi: Top Hat operation and black hat operation of Opencv image morphological processing
This column mainly introduces that if image processing is carried out through OpenCv python, the function processing prototype of OpenCv Python is understood through the principle. In specific cases, different levels and methods of processing are carried out for different images, so as to achieve a series of operations such as image denoising a ...
Posted by djumaka on Tue, 24 May 2022 06:27:11 +0300
What are your common encryption algorithms?
Encryption algorithms can be divided into reversible encryption and irreversible encryption, and reversible encryption can be divided into symmetric encryption and asymmetric encryption.
1, Irreversible encryption
Common irreversible encryption algorithms include MD5, HMAC, SHA1, SHA-224, SHA-256, SHA-384, and SHA-512. Among them, SHA-224, SHA- ...
Posted by Fearless_Fish on Tue, 24 May 2022 01:49:38 +0300
Nginx method for configuring multiple HTTPS domain names
I've been playing wechat applet recently. I have:
One ECS: CentOS 7 Multiple primary domain names During the development and testing process, for some reasons, you want to make the domain names A and B point to port 443 of the ECS at the same time and support HTTPS.
Nginx supports SNI extension of TLS protocol (multiple domain names with diff ...
Posted by the-botman on Tue, 24 May 2022 00:03:36 +0300
Follow Up: Try Trading Strategies
According to the statistical rules written above, I designed a particularly simple and rude trading strategy, which is essentially chasing the price:
Near the close, randomly select some stocks to buy from the stocks that rose by more than 5% that day, and sell them as long as they make x% profit the next day. Sell at the close if it doesn't ...
Posted by Syrehn on Mon, 23 May 2022 22:21:34 +0300
Differences between functions and methods in Python
Brief summary:
Functions that have no binding relationship with classes and instances belong to function s;
Functions bound to classes and instances belong to method s.
First of all, abandon the false cognition: not all calls in a class are called methods
Function type
Functions encapsulate some independent functions and can be called direc ...
Posted by PHPeter on Mon, 23 May 2022 22:12:54 +0300
Arrays and strings
target
1. Understand the difference between array and dynamic array.
2. Be familiar with the basic operations in array and dynamic array.
3. Be able to understand and use multidimensional arrays.
4. Understand the concept of string and the different characteristics of string.
5. Be able to use double pointer skills to solve practical probl ...
Posted by bigwatercar on Mon, 23 May 2022 21:35:07 +0300
numpy common summary
A chestnut
>>> import numpy as np
>>> a = np.arange(15).reshape(3, 5)
>>> a
array([[ 0, 1, 2, 3, 4],
[ 5, 6, 7, 8, 9],
[10, 11, 12, 13, 14]])
>>> a.shape
(3, 5)
>>> a.ndim # The number of axes of an array. In the python world, the number of axes is called rank
2
>>> a ...
Posted by evilmonkey on Mon, 23 May 2022 17:11:31 +0300
Big data acquisition case: Python web crawler instance
Web crawler:
Web crawler (also known as web page) spider , network robot, in FOAF In the middle of the community, more often referred to as web page chaser), it is a kind of automatic crawling according to certain rules web A program or script that contains information. Other names that are not often used are Ants , automatic indexing, emulator ...
Posted by lobobr on Mon, 23 May 2022 13:35:16 +0300
pytorch on GPU - training neural network with CUDA (pytorch series-30)
Running PyTorch code on GPU - neural network programming guide
In this episode, we will learn how to use GPU and PyTorch. We will see how to use the general methods of GPU, and we will see how to apply these general techniques to train our neural networks.
Deep learning using GPU
If you haven't seen the episode about why deep learning and neur ...
Posted by bmbc on Mon, 23 May 2022 12:42:05 +0300
Use of urllib Library of reptiles
urllib Library
preface
In the actual operation of the crawler, we only need two lines of code to get the web content. This function is the implementation of the third-party library
In Python 2, our library has urllib 2 and urllib, but in Python 3, we directly merged this library into urllib, which is why we can't afford to install it when we in ...
Posted by ReDucTor on Mon, 23 May 2022 11:16:21 +0300