1. Basic concepts of signals: 1. Signal mechanism When process A sends a signal to process B, once process B receives the signal, it will stop the executing process and process the signal. After processing the signal, it will continue to return to execute the previous process. It can be seen that the priority of […]
Tag: raise
Solution raise XGBoostError(_LIB.XGBGetLastError()) xgboost.core.DMatrix/Booster has not been initialized
Table of Contents Solution raise XGBoostError(_LIB.XGBGetLastError()) xgboost.core.DMatrix/Booster has not been initialized problem causes Solution 1. Check the object creation process 2. Check the object initialization process 3. Check random seed settings Summarize Sample code XGBoost library DMatrix object Solution raise XGBoostError(_LIB.XGBGetLastError()) xgboost.core.DMatrix/Booster has not been intialized Recently, when using the XGBoost library for machine learning […]
Solve graphviz\backend.py”, line 162, in pipe raise ExecutableNotFound(args) graphviz.backend.Executab
Table of Contents Resolving Graphviz ExecutableNotFound error What is Graphviz Error analysis Solution Method 1: Set environment variables Method 2: Manually set the Graphviz executable file path Summarize Resolving Graphviz ExecutableNotFound error When using Graphviz for graph visualization, you sometimes encounter the ??graphviz.backend.ExecutableNotFound?? error. This error is usually caused by not being able to find […]
uniapp implements raised icons in the middle of the navigation bar
1. Use the attribute midButton officially provided by uniapp When used, the list array must be an even number pages.json “tabBar”: { “color”: “#000”, “selectedColor”: “red”, “list”: [{ “text”: “Home”, “pagePath”: “pages/index/index”, “iconPath”: “static/logo.png”, “selectedIconPath”: “static/logo.png” }, { “text”: “mall”, “pagePath”: “pages/a/a”, “iconPath”: “static/logo.png”, “selectedIconPath”: “static/logo.png” }, // { // “text”: “Member”, // “pagePath”: “pages/b/b”, […]
Python – catching exceptions (try-except, raise) & logging module (logguru)
1. Common exceptions in Python & amp; catching exceptions 1. Common exceptions 1. NameError: name ‘a’ is not defined 2. IndexError: list index out of range 3.KeyError: ‘nam’ 4. ValueError: invalid literal for int() with base 10: ‘b’ 5.ZeroDivisionError: division by zero 2. How to analyze and solve these anomalies 1. Analysis of exceptions 1. […]
[Linux] Process Signals Part I: Signal generation (signal, kill, raise, abort, alarm), signal storage (core dump)
Article directory 1. signal function: user-defined signal capture 2. Generation of signals 1. Generate signals through interrupt buttons 2. Call system functions to send signals to the process 2.1 kill function: send any signal to any process 2.2 raise function: send any signal to the calling process 2.3 abort function: Send signal No. 6 to […]
A series of questions raised by Mybatis – Exploration of Mybatis caching mechanism
Mybatis uses two caches: local cache and second level cache. The first-level cache is enabled by default and cannot be turned off. Some key features of MyBatis (such as establishing cascade mapping through and , avoiding circular references ( circular references), accelerated repeated nested queries, etc.) are all implemented based on the MyBatis first-level cache, […]
A series of questions raised by Mybatis – spring multi data source configuration
In daily development, we use a single database for development, which can fully meet the needs in small projects. However, when we involve large-scale projects like Taobao and JD.com, a single database can hardly bear the CRUD operations of users. At this time, we need to use multiple data sources to separate read and write […]
A series of questions raised by Mybatis – dynamic SQL
Dynamic SQL is one of the powerful features of MyBatis. If you have used JDBC or other similar frameworks, you should understand how painful it is to concatenate SQL statements according to different conditions. For example, when concatenating, make sure not to forget to add necessary spaces, and also pay attention to remove the comma […]
IO advance, thread – signal communication for inter-process communication: kill(), raise(), alarm(), pause(), signal()
Signal communication 1. Introduction Signals are a simple and effective mechanism in interprocess communication for notifying a process that a certain event has occurred. When a process generates a signal, it can send the signal to other processes and trigger the signal handler function of the receiving process. The signal mechanism can be used for […]