Supplement: there is no introduction to the usage of with open in this book.
If you have a dream, you need to realize his “Python file read and write, and then use the with open statement”.
Reading and writing files is the most common IO operation. Python has built-in functions for reading and writing files, and its usage is compatible with C.
Before we read and write files, we must understand that the function of reading and writing files on disk is provided by the operating system. Modern operating systems do not allow ordinary programs to operate disk directly. So, rea...
Just take the big brothers and get it ready.
Rollen Holt 《About Python file operation “
AllenW 《PythonRead and write files
—————————————Rollen Holt—————————————
pythonThe operation of files and folders (file operation functions) involves OS modules and shutil modules.
Gets the current working directory, the directory path of the current Python script: os.getcwd ()
Returns all files and directory names in the sp...
One: plug-in storage engine
cThe terminal is connected to the s server through connectors.
Framework
SHOW ENGINES; View supported engine
SHOW table status where Engine=’InnoDB ’; Display table status information
SHOW table status\G View table status information
InnoDB Storage engine
Data are stored in table space with 2 storage formats.
1 Data and indexes of all tables of InnoDB type are stored in the same table space named ibdata1, but this approach does not support the advanced capabilities of InnoDB
2 In the configuration of asking price that...
Section 1 overview of database management system
You can see the ranking of databases in www.db-engines.com/en/ website.
The database is divided into:
Relational database:
mysql——mariaDB
oracle
Non relational database
nosql
Data management system: a more efficient data management system on disk storage mechanism.
For relational databases: Store data in tables, each table may have a correlation
Its core components: libraries, tables, indexes, views, sql, storage engines, storage functions, triggers, event schedulers
Constraints:
The p...
———Running ants in September 1, 2018
These two days in the demand for contract stamps, require that the moving end can drag the stamp, and get the coordinates of the stamp. On the Internet also read some related code, and finally sort out a demo. The code is still in bug, when the first move finger is lifted.Once again click the chapter, the coordinates will change, this point needs to be improved later.$(function(){
var cirX=0;//Center X abscissaVar cirY=0; / / center Y ordinateVar moveX=0; / / moving contact X abscissaVAR moveY=0; / / moving contact Y ordinateVar boxW=$(".Box").Width (); / / Zhang KuanVar boxH...
100A more practical promotion plan
【Https://www.toutiao.com/i6594442624734593550/
1. What is CSS?
CSS( Cascading Style Sheet )Cascading style sheets define how HTML tags are displayed.
CSSStyle consists of two components: selector and declaration. The declaration also includes the corresponding values of attributes and attributes, and each declaration ends with a semicolon.
CSSNotes: / * notes * /
Two. Introduction mode of CSS.
1. In-line styles: lt; P style = “color: red” & gt; Hello word & lt; / P & gt; where style attributes are tags for setting CSS styles
2. Internal Embedded: Simplified CSS Style Several Writte...
