从零学Python之入门(二)基本数据类型
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

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

AI Hentai Generator
Generate AI Hentai for free.

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



There is no built-in sum function in C language, so it needs to be written by yourself. Sum can be achieved by traversing the array and accumulating elements: Loop version: Sum is calculated using for loop and array length. Pointer version: Use pointers to point to array elements, and efficient summing is achieved through self-increment pointers. Dynamically allocate array version: Dynamically allocate arrays and manage memory yourself, ensuring that allocated memory is freed to prevent memory leaks.

Although distinct and distinct are related to distinction, they are used differently: distinct (adjective) describes the uniqueness of things themselves and is used to emphasize differences between things; distinct (verb) represents the distinction behavior or ability, and is used to describe the discrimination process. In programming, distinct is often used to represent the uniqueness of elements in a collection, such as deduplication operations; distinct is reflected in the design of algorithms or functions, such as distinguishing odd and even numbers. When optimizing, the distinct operation should select the appropriate algorithm and data structure, while the distinct operation should optimize the distinction between logical efficiency and pay attention to writing clear and readable code.

There is no absolute salary for Python and JavaScript developers, depending on skills and industry needs. 1. Python may be paid more in data science and machine learning. 2. JavaScript has great demand in front-end and full-stack development, and its salary is also considerable. 3. Influencing factors include experience, geographical location, company size and specific skills.

!x Understanding !x is a logical non-operator in C language. It booleans the value of x, that is, true changes to false, false changes to true. But be aware that truth and falsehood in C are represented by numerical values rather than boolean types, non-zero is regarded as true, and only 0 is regarded as false. Therefore, !x deals with negative numbers the same as positive numbers and is considered true.

There is no built-in sum function in C for sum, but it can be implemented by: using a loop to accumulate elements one by one; using a pointer to access and accumulate elements one by one; for large data volumes, consider parallel calculations.

The H5 page needs to be maintained continuously, because of factors such as code vulnerabilities, browser compatibility, performance optimization, security updates and user experience improvements. Effective maintenance methods include establishing a complete testing system, using version control tools, regularly monitoring page performance, collecting user feedback and formulating maintenance plans.

Copying and pasting the code is not impossible, but it should be treated with caution. Dependencies such as environment, libraries, versions, etc. in the code may not match the current project, resulting in errors or unpredictable results. Be sure to ensure the context is consistent, including file paths, dependent libraries, and Python versions. Additionally, when copying and pasting the code for a specific library, you may need to install the library and its dependencies. Common errors include path errors, version conflicts, and inconsistent code styles. Performance optimization needs to be redesigned or refactored according to the original purpose and constraints of the code. It is crucial to understand and debug copied code, and do not copy and paste blindly.

How to obtain dynamic data of 58.com work page while crawling? When crawling a work page of 58.com using crawler tools, you may encounter this...
