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<html lang="zh"><head><title>明解Python</title><meta charset="utf-8"/><link rel="preconnect" href="https://fonts.googleapis.com"/><link rel="preconnect" href="https://fonts.gstatic.com"/><link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=IBM Plex Mono&family=Noto Serif Simplified Chinese:wght@400;700&family=Source Sans Pro:ital,wght@0,400;0,600;1,400;1,600&display=swap"/><meta name="viewport" content="width=device-width, initial-scale=1.0"/><meta property="og:title" content="明解Python"/><meta property="og:description" content="本书图文并茂、示例丰富，采用全彩印刷方式，通过299段代码和165幅图表，系统地讲解了Python的基础语法和编程知识，内容涉及分支/循环语句、对象、字符串、列表、集合、函数、类、模块、异常处理和文件处理等。针对初学人士难以理解和容易误解的地方，本书均采用平实的语言，辅以精心设计的版式，循序渐进、清晰直观地进行了讲解。跟随本书的讲解，读者可以扎实掌握Python的基础知识，并具备实际使用Python进行编程的能力。 ..."/><meta property="og:image" content="https://wiki.7wate.com/static/og-image.png"/><meta property="og:width" content="1200"/><meta property="og:height" content="675"/><link rel="icon" href="../../../static/icon.png"/><meta name="description" content="本书图文并茂、示例丰富，采用全彩印刷方式，通过299段代码和165幅图表，系统地讲解了Python的基础语法和编程知识，内容涉及分支/循环语句、对象、字符串、列表、集合、函数、类、模块、异常处理和文件处理等。针对初学人士难以理解和容易误解的地方，本书均采用平实的语言，辅以精心设计的版式，循序渐进、清晰直观地进行了讲解。跟随本书的讲解，读者可以扎实掌握Python的基础知识，并具备实际使用Python进行编程的能力。 ..."/><meta name="generator" content="Quartz"/><link href="../../../index.css" rel="stylesheet" type="text/css" spa-preserve/><link href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.16.9/katex.min.css" rel="stylesheet" type="text/css" spa-preserve/><script src="../../../prescript.js" type="application/javascript" spa-preserve></script><script type="application/javascript" spa-preserve>const fetchData = fetch("../../../static/contentIndex.json").then(data => data.json())</script></head><body data-slug="Personal/Book/计算机/明解Python"><div id="quartz-root" class="page"><div id="quartz-body"><div class="left sidebar"><h2 class="page-title"><a href="../../..">🪴 X·Eden</a></h2><div class="spacer mobile-only"></div><div class="search"><button class="search-button" id="search-button"><p>搜索</p><svg role="img" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 19.9 19.7"><title>Search</title><g class="search-path" fill="none"><path stroke-linecap="square" d="M18.5 18.3l-5.4-5.4"></path><circle cx="8" cy="8" r="7"></circle></g></svg></button><div id="search-container"><div id="search-space"><input autocomplete="off" id="search-bar" name="search" type="text" aria-label="搜索些什么" placeholder="搜索些什么"/><div id="search-layout" data-preview="true"></div></div></div></div><button class="darkmode" id="darkmode"><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" id="dayIcon" x="0px" y="0px" viewBox="0 0 35 35" style="enable-background:new 0 0 35 35" xml:space="preserve" aria-label="暗色模式"><title>暗色模式</title><path d="M6,17.5C6,16.672,5.328,16,4.5,16h-3C0.672,16,0,16.672,0,17.5 S0.672,19,1.5,19h3C5.328,19,6,18.328,6,17.5z M7.5,26c-0.414,0-0.789,0.168-1.061,0.439l-2,2C4.168,28.711,4,29.086,4,29.5 C4,30.328,4.671,31,5.5,31c0.414,0,0.789-0.168,1.06-0.44l2-2C8.832,28.289,9,27.914,9,27.5C9,26.672,8.329,26,7.5,26z M17.5,6 C18.329,6,19,5.328,19,4.5v-3C19,0.672,18.329,0,17.5,0S16,0.672,16,1.5v3C16,5.328,16.671,6,17.5,6z M27.5,9 c0.414,0,0.789-0.168,1.06-0.439l2-2C30.832,6.289,31,5.914,31,5.5C31,4.672,30.3
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<ul>
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<li><strong>书名</strong>：《明解Python》</li>
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<li><strong>作者</strong>： 柴田望洋</li>
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<li><strong>分类</strong>： 计算机-编程设计</li>
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<li><strong>ISBN</strong>：9787115583765</li>
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<li><strong>出版社</strong>：人民邮电出版社</li>
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</ul>
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<h2 id="概述">概述<a role="anchor" aria-hidden="true" tabindex="-1" data-no-popover="true" href="#概述" class="internal"><svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"></path><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"></path></svg></a></h2>
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<p>本书图文并茂、示例丰富，采用全彩印刷方式，通过299段代码和165幅图表，系统地讲解了Python的基础语法和编程知识，内容涉及分支/循环语句、对象、字符串、列表、集合、函数、类、模块、异常处理和文件处理等。针对初学人士难以理解和容易误解的地方，本书均采用平实的语言，辅以精心设计的版式，循序渐进、清晰直观地进行了讲解。跟随本书的讲解，读者可以扎实掌握Python的基础知识，并具备实际使用Python进行编程的能力。</p>
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<h2 id="划线">划线<a role="anchor" aria-hidden="true" tabindex="-1" data-no-popover="true" href="#划线" class="internal"><svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"></path><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"></path></svg></a></h2>
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<blockquote>
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<p>编程语言各自有擅长的领域，有的擅长数值计算，有的擅长数据库和事务处理。</p>
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</blockquote>
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<blockquote>
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<p>从这方面来说，Python 可以说是一个“全能型选手”。</p>
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</blockquote>
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<blockquote>
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<p>有两个操作数的运算符称为二元运算符(binary operator)。除了二元运算符，还有存在3个操作数的运算符—— 三元运算符(trinary operator)，以及只有1个操作数的一元运算符(unary operator)。试着使用我们平时计算常用的一元运算符+和-（例1-5）。</p>
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</blockquote>
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<blockquote>
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<p>另外，Python的float型相当于C语言和Java的double型（而非float型）。Python没有double型。</p>
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</blockquote>
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<blockquote>
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<p>Python从版本3.6起可以在数值字面量字符间的任意位置插入下划线“_”（实际上Python程序会忽略下划线）（例1-8）。这样可以让位数较多的数值更易于阅读。</p>
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</blockquote>
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<blockquote>
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<p>'''和"""能以程序代码中的字符串为基础，生成类似于用户手册的程序文档。Python使用"""形式的字符串字面量来生成这种程序文档。</p>
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</blockquote>
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<blockquote>
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<p>以r或R开头的字符串字面量叫作原始字符串字面量(raw string literal)。原始字符串字面量中的转义字符按照原本含义解释。</p>
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</blockquote>
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<blockquote>
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<p>但是，变量的类型并不是固定的。试着输入例1-17中的代码确认一下结果。[插图]变量x先后“变身”为整数int型、浮点数float型和字符串str型。</p>
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</blockquote>
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<blockquote>
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<p>前面讲的变量名都只有1个字符。关于变量名，其实并不是任意名称都可以使用。命名规则大致如下。·可使用的字符包括字母、数字和下划线。·字母区分大小写。·数字不能放在变量名开头。</p>
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</blockquote>
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<blockquote>
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<p>交互式shell最后显示的值可以用变量“_”来表示。该变量在运算结果需要用于下次运算时非常有用。</p>
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</blockquote>
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<blockquote>
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<p>·作为一种迅速普及的脚本语言，Python支持多种编程范式，包括命令式编程、过程式编程、函数式编程和面向对象编程。</p>
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</blockquote>
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<blockquote>
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<p>在Python中，变量、函数、类和模块皆为对象。·对象会占一定的存储空间（内存），并且拥有标识值（用于判断是否为同一个对象）、类型和值等属性。可以使用id函数获取标识值，使用type函数获取类型。·变量只是一个和对象绑定（引用对象）的名字。·is运算符和is not运算符是身份运算符，用于判断对象是否为同一个（标识值是否相等）。在Python中，根据值是否可以改变，类型可分为两类。·可变类型： 列表、字典、集合等 ※值可以改变。·不可变类型：数字、字符串、元组等 ※值不可以改变。如果对不可变类型的变量（引用的对象）的值进行变更，则会生成新的对象，然后变量重新引用新的对象。赋值语句复制的是对象的引用而不是值。另外，赋值的对象，即等号左边的变量名如果是首次使用，程序则生成新的变量并与等号右边的对象进行绑定。[插图]与赋值语句相对应的是del语句，它用于删除作为名字的变量名。·None与任何对象都不同，是NoneType类型的特殊值。·其他编程语言使用存储期（存储空间生命周期）对变量和对象进行管理。Python与之不同，它使用引用计数，即引用对象的变量的个数，对变量和对象进行管理。·内置类型包括数值型（int型、bool型、float型和complex型）、序列型（str型、list型和tuple型等）、集合型（set型、frozenset型）和映射型（dict型）。·浮点型（float型）可以表示的值在大小和精度方面存在限制。使用sys.float_info可以查看浮点型的属性。·在进行算术运算时，程序会根据操作数的类型进行算术转换。·复数型是用表示实数部分和虚数部分的两个浮点数来表示值的类型。例如3.2 +5.7j。其中，5.7j称为虚数字面量。·因为在计算机内部，数值用位的ON/OFF来表示，所以Python可以轻易地表示二进制数。Python提供了求逻辑与的运算符&、求逻辑或的运算符|、求逻辑异或的运算符^和生成取反后的值的运算符~等按位逻辑运算符。[插图]位移运算符<<和>>将整数中的所有的位向左或向右移动后生成相应的值。[插图]</p>
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</blockquote>
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<blockquote>
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<p>不包含扩展名的文件名被直接当作模块名使用。</p>
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</blockquote>
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<blockquote>
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<p>两个程序必须放在同一个文件夹中。</p>
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</blockquote>
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<blockquote>
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<p>脚本文件：·直接执行时 变量__name__等于’<strong>main</strong>’·导入时 变量__name__等于原本的模块名（在上述程序中是min_max）</p>
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</blockquote>
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<blockquote>
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<p>如果用作包的文件夹内放置了名为’<strong>init</strong>.py’的文件，那么具备这种标准结构的包就称为标准包(regular package)。</p>
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</blockquote>
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<blockquote>
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<p>文件’<strong>init</strong>.py’用于告知Python程序当前的包是标准包。如果没有该文件，程序就无法识别出标准包（代码清单10-10也将无法执行）。·程序导入包后会初始化并执行模块’<strong>init</strong>.py’。因此，我们也会看见在模块’<strong>init</strong>.py’中插入（下一章讲解的）类定义这样的编程技巧。·在’<strong>init</strong>.py’中，如果将名称__all__定义为一个列表，其中包含对象名称的字符串，程序就可以通过*的形式导入该名称的对象。例如，在文件夹pack内的文件’<strong>init</strong>.py’中编写定义__all__ = [‘abc’, ‘xyz’]，程序就可以通过from pack import *导入pack.abc和pack.xyz。</p>
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</blockquote>
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<blockquote>
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<p>脚本程序是模块，不包含扩展名的文件名是模块名。模块是较大的代码块。·模块是一种对象，又称模块对象。在直接执行模块对象或导入模块对象时会生成并初始化模块对象。在直接执行脚本程序时，__name__的值是’<strong>main</strong>’。当其他脚本程序导入脚本程序时，__name__的值是模块名。</p>
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</blockquote>
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<blockquote>
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<p>异常处理的优点之一是可以分离原本的处理代码和处理错误的代码。</p>
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</blockquote>
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<blockquote>
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<p>[插图]</p>
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</blockquote>
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<h2 id="笔记">笔记<a role="anchor" aria-hidden="true" tabindex="-1" data-no-popover="true" href="#笔记" class="internal"><svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"></path><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"></path></svg></a></h2>
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<blockquote>
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<p>要点 变量就像一个箱子，用来存储整数、浮点数和字符串等值。把相应的值放入变量后，可以随时取出。</p>
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</blockquote>
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<p>💭 Python 称为标志也许更合适</p>
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<h2 id="书评">书评<a role="anchor" aria-hidden="true" tabindex="-1" data-no-popover="true" href="#书评" class="internal"><svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"></path><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"></path></svg></a></h2>
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<h2 id="点评">点评<a role="anchor" aria-hidden="true" tabindex="-1" data-no-popover="true" href="#点评" class="internal"><svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"></path><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"></path></svg></a></h2></article><hr/><div class="page-footer"></div></div><div class="right sidebar"><div class="graph"><h3>关系图谱</h3><div class="graph-outer"><div id="graph-container" data-cfg="{"drag":true,"zoom":true,"depth":1,"scale":1.1,"repelForce":0.5,"centerForce":0.3,"linkDistance":30,"fontSize":0.6,"opacityScale":1,"showTags":true,"removeTags":[],"focusOnHover":false}"></div><button id="global-graph-icon" aria-label="Global Graph"><svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 55 55" fill="currentColor" xml:space="preserve"><path d="M49,0c-3.309,0-6,2.691-6,6c0,1.035,0.263,2.009,0.726,2.86l-9.829,9.829C32.542,17.634,30.846,17,29,17
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