Detailed explanation of python basic knowledge
一.VariablesNaming rules
1.Variable names can only be any combination of letters, numbers, and underscores
2. Variable names cannot start with numbers
3. Some reserved words segments cannot be used as self-defined variables names
4 variable names It needs to have a clear meaning, such as a variable that saves a name, it is best to define it as a variable name such as name
2. Character encoding
The role of character encoding is to convert the input characters into Machine code. ASCII code is the earliest character encoding in the world. The earliest character encoding in China is GB2312, which contains more than 7,000 Chinese characters and symbols. After the first expansion, more than 20,000 Chinese characters were included. The character encoding is GBK1.0. The second After this expansion, a total of more than 27,000 Chinese characters were included, and the character encoding is GB18030. In order to unify character encoding internationally, Unicode character encoding was introduced because this encoding requires more storage space than the original ASCII encoding when storing English. Later, After compression optimization, UTF-8 character encoding was introduced. This encoding is still one character per byte when storing English, and three bytes when storing a Chinese character.
3. Python user interactive program
Python has a variety of interactive programs, which can also be called interpreters. The most commonly used interactive program is CPython, and the fastest code running speed is PyPy.
4.if judgment statement
#!/usr/bin/env python age_of_oldboy = 56 guess_age = int(input("guess_age:")) if guess_age == age_of_oldboy: print("yes,you got it.") elif guess_age > age_of_oldboy: print("think smaller") else: print("think bigger")
The function of this code is to allow the user to enter a number to guess the value of age_of_oldboy. It should be noted that in Python, when a line of code is not dependent on the above code The relationship needs to be entered in the top box, and when there is a subordinate relationship, a certain indentation needs to be used to express the subordinate relationship. Generally, it is indented four spaces. In addition, special statements that express judgment and looping, such as if, elif, else, while, for, etc., need to end with a : sign. This code is written in the environment of python3.X. In python2.X, do not add () to print. In python2.X, input() needs to be changed to raw_input().
5.while loop
age_of_oldboy = 56 count = 0 while count <3: guess_age = int(input("guess_age:")) if guess_age == age_of_oldboy: print("yes,you got it..") break elif guess_age > age_of_oldboy: print("think smaller...") else: print("think bigger") count += 1 if count == 3: continue_confirm = input("do you want to guessing...") if continue_confirm != 'n': count = 0
break means to end the current loop, and countinue means to skip the following loop statement and start the next loop. You can write an else statement after the while loop. When the loop ends normally, that is, if no break, countinue, etc. actions have been performed, the actions under the else statement will be executed.
6. for loop
for count in range(3): guess_age = int(input("guess_age:")) if guess_age == age_of_oldboy: print("yes,you got it..") break elif guess_age > age_of_oldboy: print("think smaller...") else: print("think bigger") else: print("sorry,you try too mary times..") for i in range(0,10,2): #range(初值,条件,步长) print(i)
7. Quote Variable method
1 Use placeholder
name=input("name:") age=input("age:") job=input("job:") salary=input("salary:") info='''-----info of %s----- Name:%s Age:%s Job:%s Salary:%s '''% (name,name,age,job,salary)
Use placeholder %s to indicate that the position needs to be filled with a string , followed by % It is the string used to fill the previous placeholder position, and the variable can be referenced at this position. Other placeholders include %d and %f respectively indicating filling with integer type and filling with floating point type
info2='''-----info of {_name}----- Name:{_name} Age:{_age} Job:{_job} Salary:{_salary} '''.format(_name=name,_age=age,_job=job,_salary=salary) info3='''-----info of {0}----- Name:{0} Age:{1} Job:{2} Salary:{3} '''.format(name,age,job,salary)
8.''' The role of '''
1Multi-line comments
'''-----info of {0}----- Name:{0} Age:{1} Job:{2} Salary:{3} '''
2Multi-line output
info3='''-----info of {0}----- Name:{0} Age:{1} Job:{2} Salary:{3} ''' print(info3)
The above is the detailed content of Detailed explanation of python basic knowledge. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

VS Code can run on Windows 8, but the experience may not be great. First make sure the system has been updated to the latest patch, then download the VS Code installation package that matches the system architecture and install it as prompted. After installation, be aware that some extensions may be incompatible with Windows 8 and need to look for alternative extensions or use newer Windows systems in a virtual machine. Install the necessary extensions to check whether they work properly. Although VS Code is feasible on Windows 8, it is recommended to upgrade to a newer Windows system for a better development experience and security.

VS Code can be used to write Python and provides many features that make it an ideal tool for developing Python applications. It allows users to: install Python extensions to get functions such as code completion, syntax highlighting, and debugging. Use the debugger to track code step by step, find and fix errors. Integrate Git for version control. Use code formatting tools to maintain code consistency. Use the Linting tool to spot potential problems ahead of time.

Running Python code in Notepad requires the Python executable and NppExec plug-in to be installed. After installing Python and adding PATH to it, configure the command "python" and the parameter "{CURRENT_DIRECTORY}{FILE_NAME}" in the NppExec plug-in to run Python code in Notepad through the shortcut key "F6".

VS Code extensions pose malicious risks, such as hiding malicious code, exploiting vulnerabilities, and masturbating as legitimate extensions. Methods to identify malicious extensions include: checking publishers, reading comments, checking code, and installing with caution. Security measures also include: security awareness, good habits, regular updates and antivirus software.
