break语句用来终止循环语句，即循环条件没有False条件或者序列还没被完全递归完，也会停止执行循环语句。

break语句用在while和for循环中。

如果您使用嵌套循环，break语句将停止执行最深层的循环，并开始执行下一行代码。

Python语言 break 语句语法：

break

示例一：

<pre style="" class="prettyprint prettyprinted"><span class="com">#!/usr/bin/python</span><span class="pln">

</span><span class="kwd">for</span><span class="pln"> letter </span><span class="kwd">in</span><span class="pln"> </span><span class="str">'Praifire'</span><span class="pun">:</span><span class="pln">    </span><span class="pln">
   </span><span class="kwd">if</span><span class="pln"> letter </span><span class="pun">==</span><span class="pln"> </span><span class="str">'fire'</span><span class="pun">:</span><span class="pln">
      </span><span class="kwd">break</span><span class="pln">
   </span><span class="kwd">print</span><span class="pln"> </span><span class="str">'Current Letter :'</span><span class="pun">,</span><span class="pln"> letter</span>

输出结果：

Current Letter : P
Current Letter : r
Current Letter : a
Current Letter : i
Current Letter : f
Current Letter : i
Current Letter : r
Current Letter : e

示例二：

<pre name="code" class="python"><pre style="" class="prettyprint prettyprinted"><span class="com">#!/usr/bin/python</span><span class="pln"></span>

var = 10 while var > 0: print 'Current variable value :', var var = var -1 if var == 5: breakprint "Praifire,Good bye!"

输出结果：

Current variable value : 10
Current variable value : 9
Current variable value : 8
Current variable value : 7
Current variable value : 6
Praifire,Good bye!