<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br></pre></td><tdclass="code"><pre><spanclass="line">message = input(<spanclass="string">"Please tell me your name:"</span>)</span><br><spanclass="line">print(<spanclass="string">"Hello , "</span> + message + <spanclass="string">"!"</span>)</span><br></pre></td></tr></table></figure>
<p>输出结果如下:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br></pre></td><tdclass="code"><pre><spanclass="line">Please tell me your name:anliy</span><br><spanclass="line">Hello , anliy!</span><br></pre></td></tr></table></figure>
<p>进阶:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br></pre></td><tdclass="code"><pre><spanclass="line">message = <spanclass="string">"Please tell me your name so that we can personalize the messages you see."</span></span><br><spanclass="line">message += <spanclass="string">"\nWhat's your first name?"</span></span><br><spanclass="line">name = input(message)</span><br><spanclass="line">print(<spanclass="string">"\nHello , "</span> + name + <spanclass="string">"!"</span>)</span><br></pre></td></tr></table></figure>
<p>输出结果如下:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br></pre></td><tdclass="code"><pre><spanclass="line">Please tell me your name so that we can personalize the messages you see.</span><br><spanclass="line">What<spanclass="string">'s your first name?trhx</span></span><br><spanclass="line"><spanclass="string"></span></span><br><spanclass="line"><spanclass="string">Hello , trhx!</span></span><br></pre></td></tr></table></figure>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br></pre></td><tdclass="code"><pre><spanclass="line"><spanclass="meta">>>></span>age = input(<spanclass="string">"How old are you?"</span>)</span><br><spanclass="line">How old are you?19</span><br><spanclass="line"><spanclass="meta">>>></span>age</span><br><spanclass="line"><spanclass="string">'19'</span></span><br></pre></td></tr></table></figure>
<p>为了解决这个问题,可以使用函数 int() ,它让Python将输入视为数值:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br></pre></td><tdclass="code"><pre><spanclass="line"><spanclass="meta">>>></span>age = input(<spanclass="string">"How old are you?"</span>)</span><br><spanclass="line">How old are you?19</span><br><spanclass="line"><spanclass="meta">>>></span>age = int(age)</span><br><spanclass="line"><spanclass="meta">>>></span>age</span><br><spanclass="line"><spanclass="number">19</span></span><br></pre></td></tr></table></figure>
<p>实例:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br></pre></td><tdclass="code"><pre><spanclass="line">age = input(<spanclass="string">"Please tell me your age:"</span>)</span><br><spanclass="line">age = int(age)</span><br><spanclass="line"><spanclass="keyword">if</span> age >= <spanclass="number">18</span>:</span><br><spanclass="line"> print(<spanclass="string">"You are old enough to go to the Internet bar!"</span>)</span><br><spanclass="line"><spanclass="keyword">else</span>:</span><br><spanclass="line"> print(<spanclass="string">"You are not old enough to go to Internet bar!"</span>)</span><br></pre></td></tr></table></figure>
<p>输出结果如下:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br></pre></td><tdclass="code"><pre><spanclass="line">Please tell me your age:<spanclass="number">17</span></span><br><spanclass="line">You are <spanclass="keyword">not</span> old enough to go to Internet bar!</span><br></pre></td></tr></table></figure>
<h1id="6-2-while-循环"><ahref="#6-2-while-循环"class="headerlink"title=" - 6.2 while 循环 "></a><fontcolor="#FF0000"> - 6.2 while 循环 </font></h1><p> for 循环用于针对集合中的每一个元素的一个代码块,而 while 循环不断地运行,直到指定的条件不满足为止</p>
<h1id="6-2-1-使用-while-循环"><ahref="#6-2-1-使用-while-循环"class="headerlink"title=" - 6.2.1 使用 while 循环 "></a><fontcolor="#FF0000"> - 6.2.1 使用 while 循环 </font></h1><p> 一个简单的 while 循环:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br></pre></td><tdclass="code"><pre><spanclass="line">num = <spanclass="number">1</span></span><br><spanclass="line"><spanclass="keyword">while</span> num <<spanclass="number">5</span>:</span><br><spanclass="line"> print(num)</span><br><spanclass="line"> num += <spanclass="number">1</span></span><br></pre></td></tr></table></figure>
<h1id="6-2-2-让用户选择退出循环"><ahref="#6-2-2-让用户选择退出循环"class="headerlink"title=" - 6.2.2 让用户选择退出循环 "></a><fontcolor="#FF0000"> - 6.2.2 让用户选择退出循环 </font></h1><figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br></pre></td><tdclass="code"><pre><spanclass="line">prompt = <spanclass="string">"\nTell me something, and I will repeat it back to you:"</span></span><br><spanclass="line">prompt += <spanclass="string">"\nEnter 'quit' to end the program."</span></span><br><spanclass="line">message = <spanclass="string">" "</span></span><br><spanclass="line"><spanclass="keyword">while</span> message != <spanclass="string">'quit'</span>:</span><br><spanclass="line"> message = input(prompt)</span><br><spanclass="line"> print(message)</span><br></pre></td></tr></table></figure>
<p>运行程序:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br><spanclass="line">7</span><br><spanclass="line">8</span><br><spanclass="line">9</span><br><spanclass="line">10</span><br><spanclass="line">11</span><br><spanclass="line">12</span><br></pre></td><tdclass="code"><pre><spanclass="line"></span><br><spanclass="line">Tell me something, <spanclass="keyword">and</span> I will repeat it back to you:</span><br><spanclass="line">Enter <spanclass="string">'quit'</span> to end the program.Hello everyone!</span><br><spanclass="line">Hello everyone!</span><br><spanclass="line"></span><br><spanclass="line">Tell me something, <spanclass="keyword">and</span> I will repeat it back to you:</span><br><spanclass="line">Enter <spanclass="string">'quit'</span> to end the program.Hello again!</span><br><spanclass="line">Hello again!</span><br><spanclass="line"></span><br><spanclass="line">Tell me something, <spanclass="keyword">and</span> I will repeat it back to you:</span><br><spanclass="line">Enter <spanclass="string">'quit'</span> to end the program.quit</span><br><spanclass="line">quit</span><br></pre></td></tr></table></figure>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br><spanclass="line">7</span><br><spanclass="line">8</span><br><spanclass="line">9</span><br></pre></td><tdclass="code"><pre><spanclass="line">prompt = <spanclass="string">"\nTell me something, and I will repeat it back to you:"</span></span><br><spanclass="line">prompt += <spanclass="string">"\nEnter 'quit' to end the program."</span></span><br><spanclass="line">active = <spanclass="keyword">True</span></span><br><spanclass="line"><spanclass="keyword">while</span> active:</span><br><spanclass="line"> message = input(prompt)</span><br><spanclass="line"><spanclass="keyword">if</span> message == <spanclass="string">'quit'</span>:</span><br><spanclass="line"> active = <spanclass="keyword">False</span></span><br><spanclass="line"><spanclass="keyword">else</span>:</span><br><spanclass="line"> print(message)</span><br></pre></td></tr></table></figure>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br><spanclass="line">7</span><br><spanclass="line">8</span><br><spanclass="line">9</span><br></pre></td><tdclass="code"><pre><spanclass="line">prompt = <spanclass="string">"\nPlease enter the name of a city you have visited:"</span></span><br><spanclass="line">prompt += <spanclass="string">"\nEnter 'quit' when you are finished."</span></span><br><spanclass="line">active = <spanclass="keyword">True</span></span><br><spanclass="line"><spanclass="keyword">while</span> active:</span><br><spanclass="line"> city = input(prompt)</span><br><spanclass="line"><spanclass="keyword">if</span> city == <spanclass="string">'quit'</span>:</span><br><spanclass="line"><spanclass="keyword">break</span></span><br><spanclass="line"><spanclass="keyword">else</span>:</span><br><spanclass="line"> print(<spanclass="string">"I'd love to go to "</span> + city.title() + <spanclass="string">"!"</span>)</span><br></pre></td></tr></table></figure>
<p>运行程序:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br><spanclass="line">7</span><br><spanclass="line">8</span><br><spanclass="line">9</span><br><spanclass="line">10</span><br><spanclass="line">11</span><br></pre></td><tdclass="code"><pre><spanclass="line"></span><br><spanclass="line">Please enter the name of a city you have visited:</span><br><spanclass="line">Enter <spanclass="string">'quit'</span> when you are finished.Shanghai</span><br><spanclass="line">I<spanclass="string">'d love to go to Shanghai!</span></span><br><spanclass="line"><spanclass="string"></span></span><br><spanclass="line"><spanclass="string">Please enter the name of a city you have visited:</span></span><br><spanclass="line"><spanclass="string">Enter '</span>quit<spanclass="string">' when you are finished.Beijing</span></span><br><spanclass="line"><spanclass="string">I'</span>d love to go to Beijing!</span><br><spanclass="line"></span><br><spanclass="line">Please enter the name of a city you have visited:</span><br><spanclass="line">Enter <spanclass="string">'quit'</span> when you are finished.quit</span><br></pre></td></tr></table></figure>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br></pre></td><tdclass="code"><pre><spanclass="line">number =<spanclass="number">0</span></span><br><spanclass="line"><spanclass="keyword">while</span> number <<spanclass="number">10</span>:</span><br><spanclass="line"> number += <spanclass="number">1</span></span><br><spanclass="line"><spanclass="keyword">if</span> number % <spanclass="number">2</span> == <spanclass="number">0</span>:</span><br><spanclass="line"><spanclass="keyword">continue</span></span><br><spanclass="line"> print(number)</span><br></pre></td></tr></table></figure>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br><spanclass="line">7</span><br><spanclass="line">8</span><br></pre></td><tdclass="code"><pre><spanclass="line">Verifying user: Candace</span><br><spanclass="line">Verifying user: Brian</span><br><spanclass="line">Verifying user: Alice</span><br><spanclass="line"></span><br><spanclass="line">The following users have been confirmed:</span><br><spanclass="line">Candace</span><br><spanclass="line">Brian</span><br><spanclass="line">Alice</span><br></pre></td></tr></table></figure>
<h1id="6-3-3-使用用户输入来填充字典"><ahref="#6-3-3-使用用户输入来填充字典"class="headerlink"title=" - 6.3.3 使用用户输入来填充字典 "></a><fontcolor="#FF0000"> - 6.3.3 使用用户输入来填充字典 </font></h1><figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br><spanclass="line">7</span><br><spanclass="line">8</span><br><spanclass="line">9</span><br><spanclass="line">10</span><br><spanclass="line">11</span><br><spanclass="line">12</span><br><spanclass="line">13</span><br><spanclass="line">14</span><br><spanclass="line">15</span><br><spanclass="line">16</span><br><spanclass="line">17</span><br><spanclass="line">18</span><br><spanclass="line">19</span><br><spanclass="line">20</span><br><spanclass="line">21</span><br><spanclass="line">22</span><br></pre></td><tdclass="code"><pre><spanclass="line">responses = {}</span><br><spanclass="line"></span><br><spanclass="line"><spanclass="comment">#设置一个标志,指出调查是否继续</span></span><br><spanclass="line">polling_active = <spanclass="keyword">True</span></span><br><spanclass="line"></span><br><spanclass="line"><spanclass="keyword">while</span> polling_active:</span><br><spanclass="line"><spanclass="comment">#提示输入被调查者的姓名和回答</span></span><br><spanclass="line"> name = input(<spanclass="string">"\nWhat's your name?"</span>)</span><br><spanclass="line"> response = input(<spanclass="string">"What kind of fruit do you like?"</span>)</span><br><spanclass="line"></span><br><spanclass="line"><spanclass="comment">#将答卷储存在字典中</span></span><br><spanclass="line"> responses[name] = response</span><br><spanclass="line"></span><br><spanclass="line"><spanclass="comment">#询问是否还有其他人要参与回答</span></span><br><spanclass="line"> repeat = input(<spanclass="string">"Would you like to let another person respond?(Yes/No)"</span>)</span><br><spanclass="line"><spanclass="keyword">if</span> repeat == <spanclass="string">'No'</span>:</span><br><spanclass="line"> polling_active = <spanclass="keyword">False</span></span><br><spanclass="line"></span><br><spanclass="line"><spanclass="comment">#调查结束,显示结果</span></span><br><spanclass="line">print(<spanclass="string">"\n------ Poll Results ------"</span>)</span><br><spanclass="line"><spanclass="keyword">for</span> name , response <spanclass="keyword">in</span> responses.items():</span><br><spanclass="line"> print(name + <spanclass="string">" like "</span> + response + <spanclass="string">"."</span>)</span><br></pre></td></tr></table></figure>
<p>运行程序:</p>
<figureclass="highlight python"><table><tr><tdclass="gutter"><pre><spanclass="line">1</span><br><spanclass="line">2</span><br><spanclass="line">3</span><br><spanclass="line">4</span><br><spanclass="line">5</span><br><spanclass="line">6</span><br><spanclass="line">7</span><br><spanclass="line">8</span><br><spanclass="line">9</span><br><spanclass="line">10</span><br><spanclass="line">11</span><br></pre></td><tdclass="code"><pre><spanclass="line">What<spanclass="string">'s your name?TRHX</span></span><br><spanclass="line"><spanclass="string">What kind of fruit do you like?apple</span></span><br><spanclass="line"><spanclass="string">Would you like to let another person respond?(Yes/No)Yes</span></span><br><spanclass="line"><spanclass="string"></span></span><br><spanclass="line">What's your name?TRHXCC</span><br><spanclass="line">What kind of fruit do you like?banana</span><br><spanclass="line">Would you like to let another person respond?(Yes/No)No</span><br><spanclass="line"></span><br><spanclass="line">------ Poll Results ------</span><br><spanclass="line">TRHX like apple.</span><br><spanclass="line">TRHXCC like banana.</span><br></pre></td></tr></table></figure>