最後更新日期：2025 年 02 月 25 日

Table of Contents

一、建立字串

在 Python 3 中，字串是一連串有序的 Unicode 字元，是的，與 Python 2 不同，Python3 預設的編碼就是 Unicode。

在 Python 中，字串可以被括在單引號 ( ' ) 中，或是雙引號 ( " ) 中，或是三引號 (""" 或 ''') 中。

<span class="line"><span style="color: #D8DEE9FF">str1 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">Hello World.</span><span style="color: #EBCB8B">\n</span><span style="color: #ECEFF4">'</span></span>
<span class="line"><span style="color: #D8DEE9FF">str2 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">Hello World.</span><span style="color: #EBCB8B">\n</span><span style="color: #ECEFF4">"</span></span>
<span class="line"><span style="color: #D8DEE9FF">str3 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'''</span><span style="color: #EBCB8B">\n</span><span style="color: #A3BE8C">This is line one</span></span>
<span class="line"><span style="color: #A3BE8C">                this is line two.</span><span style="color: #ECEFF4">'''</span></span>

使用單引號和雙引號並沒有任何區別，只是看你的使用習慣而已，其中的特殊字元都會被轉義，除非你特別指定該字串不轉義。

被三引號括住的稱為 docstrings，因為它們主要用於說明函式的用途。

被單引號和雙引號所括住的字串無法跨越多列，我們必須在同一列中以對應的引號結束字串，但 docstrings 可以跨越多列。

引號的混用有時會造成一些困擾，我們可以參考 PEP 8 及 PEP 257 的指導方針來使用會比較好一點。

二、常用的字串函式

print() 印出字串

<span class="line"><span style="color: #D8DEE9FF">a </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">apple</span><span style="color: #ECEFF4">'</span></span>
<span class="line"><span style="color: #D8DEE9FF">b </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">banana</span><span style="color: #ECEFF4">"</span></span>
<span class="line"><span style="color: #D8DEE9FF">c </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'''</span><span style="color: #A3BE8C">cherry</span><span style="color: #ECEFF4">'''</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 格式化輸出</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">There are </span><span style="color: #EBCB8B">%d</span><span style="color: #A3BE8C"> fruits in the basket: </span><span style="color: #EBCB8B">%s</span><span style="color: #A3BE8C">, </span><span style="color: #EBCB8B">%s</span><span style="color: #A3BE8C">, </span><span style="color: #EBCB8B">%s</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">3</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> a</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> b</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> c</span><span style="color: #ECEFF4">))</span></span>
<span class="line"></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%8d</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">1234</span><span style="color: #ECEFF4">))</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 寬度 8，靠右對齊</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%-8d</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">1234</span><span style="color: #ECEFF4">))</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 寬度 8，靠左對齊</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%08d</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">1234</span><span style="color: #ECEFF4">))</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 寬度 8，靠右對齊，空格補 0</span></span>
<span class="line"></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%8s</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">ABCDEF</span><span style="color: #ECEFF4">"</span><span style="color: #ECEFF4">))</span><span style="color: #D8DEE9FF"> </span><span style="color: #616E88"># 寬度 8，靠右對齊</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%5s</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">ABCDEF</span><span style="color: #ECEFF4">"</span><span style="color: #ECEFF4">))</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 寬度 5，超過全顯示</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%5.3s</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">ABCDEF</span><span style="color: #ECEFF4">"</span><span style="color: #ECEFF4">))</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 寬度 5，超過只顯示 3 個</span></span>
<span class="line"></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%d</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">15</span><span style="color: #ECEFF4">))</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%o</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">15</span><span style="color: #ECEFF4">))</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%#o</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">15</span><span style="color: #ECEFF4">))</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%x</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">15</span><span style="color: #ECEFF4">))</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #EBCB8B">%#x</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">%</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">15</span><span style="color: #ECEFF4">))</span></span>

len()-取得字串的長度

<span class="line"><span style="color: #D8DEE9FF">str1 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">Hello</span><span style="color: #ECEFF4">'</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #88C0D0">len</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">))</span></span>

str()-強制轉換型別為字串

Python 不會自動轉換型別，所以有時我們必須手動操作

<span class="line"><span style="color: #88C0D0">str</span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">99.8</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF"> </span><span style="color: #616E88"># "99.8"</span></span>
<span class="line"><span style="color: #88C0D0">str</span><span style="color: #ECEFF4">(</span><span style="color: #81A1C1">True</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF"> </span><span style="color: #616E88"># "True"</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF">price </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #B48EAD">50</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">price</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 這樣 ok</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">Price: </span><span style="color: #ECEFF4">"</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> price</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 這樣也行</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">Price: </span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">+</span><span style="color: #D8DEE9FF"> </span><span style="color: #88C0D0">str</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">price</span><span style="color: #ECEFF4">))</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 必須轉換型別</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">Price: </span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">+</span><span style="color: #D8DEE9FF"> price</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 這樣會有錯誤，因為字串連結運算子只能用在字串型別</span></span>

三、字串物件可以使用的方法

在 Python 中，所有的資料型態都是物件，可以使用其對應的物件方法

<span class="line"><span style="color: #D8DEE9FF">str1 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C"> TexT </span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 前後都有空白</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 去除掉前後的空白，</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">strip</span><span style="color: #ECEFF4">()</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 去除掉左邊的空白</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">lstrip</span><span style="color: #ECEFF4">()</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 去除掉右邊的空白</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">rstrip</span><span style="color: #ECEFF4">()</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 找到出現 ex 的位置</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">find</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">ex</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">)</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 全轉為大寫</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">upper</span><span style="color: #ECEFF4">()</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 全轉為小寫</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">lower</span><span style="color: #ECEFF4">()</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 大小寫互換</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">swapcase</span><span style="color: #ECEFF4">()</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 首字大寫</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">capitalize</span><span style="color: #ECEFF4">()</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 這不會作用，因為首字為空白</span></span>
<span class="line"><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">strip</span><span style="color: #ECEFF4">().</span><span style="color: #88C0D0">capitalize</span><span style="color: #ECEFF4">()</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 必須先去除空白</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 字串取代</span></span>
<span class="line"><span style="color: #D8DEE9FF">str2 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">Hello world</span><span style="color: #ECEFF4">'</span></span>
<span class="line"><span style="color: #D8DEE9FF">str2</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">replace</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">world</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">python</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">)</span></span>

四、字串的部份取值-slice

索引運算子(Index Operator)-取出指定位置的字元

字串可以被視為一種串列 (List)，所以可以迭代它；也可以使用「[ ]」索引運算子取出指定位置的字元

<span class="line"><span style="color: #D8DEE9FF">letters </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">abcdefghijklmnopqrstuvwxyz</span><span style="color: #ECEFF4">"</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">letters</span><span style="color: #ECEFF4">[</span><span style="color: #B48EAD">1</span><span style="color: #ECEFF4">])</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 印出 b</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF">str1 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">Hello</span><span style="color: #ECEFF4">'</span></span>
<span class="line"><span style="color: #81A1C1">for</span><span style="color: #D8DEE9FF"> c </span><span style="color: #81A1C1">in</span><span style="color: #D8DEE9FF"> str1</span><span style="color: #ECEFF4">:</span></span>
<span class="line"><span style="color: #D8DEE9FF">    </span><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">c</span><span style="color: #ECEFF4">)</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 也會印出 Hello</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #B48EAD">0</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #B48EAD">1</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #B48EAD">2</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #B48EAD">3</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #B48EAD">4</span><span style="color: #ECEFF4">])</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88"># 還是會印出 Hello</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #81A1C1">-</span><span style="color: #B48EAD">5</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #81A1C1">-</span><span style="color: #B48EAD">4</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #81A1C1">-</span><span style="color: #B48EAD">3</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #81A1C1">-</span><span style="color: #B48EAD">2</span><span style="color: #ECEFF4">])</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">[</span><span style="color: #81A1C1">-</span><span style="color: #B48EAD">1</span><span style="color: #ECEFF4">])</span></span>

參考：https://runestone.academy/ns/books/published//thinkcspy/Strings/IndexOperatorWorkingwiththeCharactersofaString.html

切片運算子 (Slicing Operator)-取出指定位置範圍的字串

<span class="line"><span style="color: #D8DEE9FF">letters </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">abcdefghijklmnopqrstuvwxyz</span><span style="color: #ECEFF4">"</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">letters</span><span style="color: #ECEFF4">[</span><span style="color: #B48EAD">1</span><span style="color: #ECEFF4">:</span><span style="color: #B48EAD">4</span><span style="color: #ECEFF4">])</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 印出 bcd</span></span>

參考：

https://runestone.academy/ns/books/published//fopp/Sequences/TheSliceOperator.html

五、字串的組合與分割

基本的組合方式

<span class="line"><span style="color: #D8DEE9FF">letters </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">abc</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">+</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">def</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># "abcdef"</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF">letters </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">abc</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">+</span><span style="color: #D8DEE9FF"> </span><span style="color: #88C0D0">str</span><span style="color: #ECEFF4">(</span><span style="color: #B48EAD">123</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># "abc123"，數字型別必須轉換為字串</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF">letters </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">abc</span><span style="color: #ECEFF4">"</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">*</span><span style="color: #D8DEE9FF"> </span><span style="color: #B48EAD">3</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># "abcabcabc"</span></span>

還可以像 PHP 的 implode

<span class="line"><span style="color: #D8DEE9FF">fruits </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">[</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">apple</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">banana</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">cherry</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">]</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF">str1 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C"> </span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">join</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">fruits</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 使用空白將字串組合</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str1</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 'apple banana cherry'</span></span>
<span class="line"></span>
<span class="line"><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">-</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">join</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">fruits</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 使用 - 將字串組合</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">str2</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 'apple-banana-cherry' </span></span>

參考：

https://www.digitalocean.com/community/tutorials/python-string-concatenation

.split()-將字串切為串列 (List)

這有點像 PHP 的 explode，可以將字串依特定的分隔字元切分成字串組成的串列 (List)

<span class="line"><span style="color: #D8DEE9FF">str1 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">apple banana cherry</span><span style="color: #ECEFF4">"</span></span>
<span class="line"><span style="color: #D8DEE9FF">list1 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> str1</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">split</span><span style="color: #ECEFF4">()</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># 預設的分隔字元是空白</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">list1</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># ['apple', 'banana', 'cherry']</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF">str2 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">"</span><span style="color: #A3BE8C">apple, banana, cherry</span><span style="color: #ECEFF4">"</span></span>
<span class="line"><span style="color: #D8DEE9FF">list2 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> str2</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">split</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">,</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">)</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">list2</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># ['apple', ' banana', ' cherry'] 注意！字串裏會有空白</span></span>
<span class="line"><span style="color: #D8DEE9FF">list3 </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> str2</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">split</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">, </span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">)</span></span>
<span class="line"><span style="color: #88C0D0">print</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">list3</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF">  </span><span style="color: #616E88"># ['apple', 'banana', 'cherry']</span></span>

<a href="https://stackoverflow.com/questions/3854867/what-is-for-python-what-explode-is-for-php">https://stackoverflow.com/questions/3854867/what-is-for-python-what-explode-is-for-php</a>

Python 3 – 字串 – 基本操作