简单的数据类型以及赋值
变量不需要声明
Python的变量不需要声明,你可以直接输入:
代码如下:
>>>a = 10
那么你的内存里就有了一个变量a, 它的值是10,它的类型是integer (整数)。 在此之前你不需要做什么特别的声明,而数据类型是Python自动决定的。
代码如下:
>>>print a
>>>print type(a)
那么会有如下输出
代码如下:
10
这里,我们学到一个内置函数type(), 用以查询变量的类型。
回收变量名
如果你想让a存储不同的数据,你不需要删除原有变量就可以直接赋值。
代码如下:
>>>a = 1.3
>>>print a,type(a)
会有如下输出
代码如下:
1.3
我们看到print的另一个用法,也就是print后跟多个输出,以逗号分隔。
基本数据类型
代码如下:
a=10 # int 整数
a=1.3 # float 浮点数
a=True # 真值 (True/False)
a='Hello!' # 字符串
以上是最常用的数据类型,对于字符串来说,也可以用双引号。
(此外还有分数,字符,复数等其他数据类型,有兴趣的可以学习一下)
总结
变量不需要声明,不需要删除,可以直接回收适用。
type(): 查询数据类型
整数,浮点数,真值,字符串

Pythonusesahybridmodelofcompilationandinterpretation:1)ThePythoninterpretercompilessourcecodeintoplatform-independentbytecode.2)ThePythonVirtualMachine(PVM)thenexecutesthisbytecode,balancingeaseofusewithperformance.

Pythonisbothinterpretedandcompiled.1)It'scompiledtobytecodeforportabilityacrossplatforms.2)Thebytecodeistheninterpreted,allowingfordynamictypingandrapiddevelopment,thoughitmaybeslowerthanfullycompiledlanguages.

Forloopsareidealwhenyouknowthenumberofiterationsinadvance,whilewhileloopsarebetterforsituationswhereyouneedtoloopuntilaconditionismet.Forloopsaremoreefficientandreadable,suitableforiteratingoversequences,whereaswhileloopsoffermorecontrolandareusefulf

Forloopsareusedwhenthenumberofiterationsisknowninadvance,whilewhileloopsareusedwhentheiterationsdependonacondition.1)Forloopsareidealforiteratingoversequenceslikelistsorarrays.2)Whileloopsaresuitableforscenarioswheretheloopcontinuesuntilaspecificcond

Pythonisnotpurelyinterpreted;itusesahybridapproachofbytecodecompilationandruntimeinterpretation.1)Pythoncompilessourcecodeintobytecode,whichisthenexecutedbythePythonVirtualMachine(PVM).2)Thisprocessallowsforrapiddevelopmentbutcanimpactperformance,req

ToconcatenatelistsinPythonwiththesameelements,use:1)the operatortokeepduplicates,2)asettoremoveduplicates,or3)listcomprehensionforcontroloverduplicates,eachmethodhasdifferentperformanceandorderimplications.

Pythonisaninterpretedlanguage,offeringeaseofuseandflexibilitybutfacingperformancelimitationsincriticalapplications.1)InterpretedlanguageslikePythonexecuteline-by-line,allowingimmediatefeedbackandrapidprototyping.2)CompiledlanguageslikeC/C transformt

Useforloopswhenthenumberofiterationsisknowninadvance,andwhileloopswheniterationsdependonacondition.1)Forloopsareidealforsequenceslikelistsorranges.2)Whileloopssuitscenarioswheretheloopcontinuesuntilaspecificconditionismet,usefulforuserinputsoralgorit


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

SublimeText3 English version
Recommended: Win version, supports code prompts!

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

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

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
