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<h1 id="3-函数的参数">3. 函数的参数</h1>
<p>​ 定义函数的时候，把参数的名字和位置确定下来，函数的接口定义就完成了。对于函数的调用者来说，只需要知道如何传递正确的参数，以及函数将返回什么样的值，而函数内部的复杂逻辑被封装起来，调用者无需了解。</p>
<h2 id="31-位置参数">3.1 位置参数</h2>
<p>​ 位置参数，即传入的参数有位置顺序区分。例如以下的<code>x</code>和<code>n</code>根据位置不同，接收对应位置的传入参数。</p>
<pre class="language-"><code class="lang-python"><span class="token keyword">def</span> <span class="token function">power</span><span class="token punctuation">(</span>x<span class="token punctuation">,</span> n<span class="token punctuation">)</span><span class="token punctuation">:</span>
s <span class="token operator">=</span> <span class="token number">1</span>
<span class="token keyword">while</span> n <span class="token operator">></span> <span class="token number">0</span><span class="token punctuation">:</span>
n <span class="token operator">=</span> n <span class="token operator">-</span> <span class="token number">1</span>
s <span class="token operator">=</span> s <span class="token operator">*</span> x
<span class="token keyword">return</span> s
</code></pre>
<h2 id="32-默认参数">3.2 默认参数</h2>
<p>​ 默认参数，即对某个参数设置默认值，如果没有传入该参数则使用默认值，如果有传入该参数则使用传入值。</p>
<ul>
<li>必须参数在前，默认参数在后</li>
</ul>
<ul>
<li>一般将变化小的参数设置为默认参数，变化大的设置为必选参数</li>
</ul>
<pre class="language-"><code class="lang-python"><span class="token comment">#函数定义</span>
<span class="token keyword">def</span> <span class="token function">power</span><span class="token punctuation">(</span>x<span class="token punctuation">,</span> n<span class="token operator">=</span><span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">:</span>
s <span class="token operator">=</span> <span class="token number">1</span>
<span class="token keyword">while</span> n <span class="token operator">></span> <span class="token number">0</span><span class="token punctuation">:</span>
n <span class="token operator">=</span> n <span class="token operator">-</span> <span class="token number">1</span>
s <span class="token operator">=</span> s <span class="token operator">*</span> x
<span class="token keyword">return</span> s
<span class="token comment">#函数调用 </span>
<span class="token operator">>></span><span class="token operator">></span> power<span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">)</span>
<span class="token number">25</span>
<span class="token operator">>></span><span class="token operator">></span> power<span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">)</span>
<span class="token number">125</span>
</code></pre>
<p>有多个默认参数时，可以按顺序提供默认参数，也可以指定默认参数的参数名传值而不按参数顺序。例如：</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#函数定义</span>
<span class="token keyword">def</span> <span class="token function">enroll</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> gender<span class="token punctuation">,</span> age<span class="token operator">=</span><span class="token number">6</span><span class="token punctuation">,</span> city<span class="token operator">=</span><span class="token string">'Beijing'</span><span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token keyword">print</span><span class="token punctuation">(</span><span class="token string">'name:'</span><span class="token punctuation">,</span> name<span class="token punctuation">)</span>
<span class="token keyword">print</span><span class="token punctuation">(</span><span class="token string">'gender:'</span><span class="token punctuation">,</span> gender<span class="token punctuation">)</span>
<span class="token keyword">print</span><span class="token punctuation">(</span><span class="token string">'age:'</span><span class="token punctuation">,</span> age<span class="token punctuation">)</span>
<span class="token keyword">print</span><span class="token punctuation">(</span><span class="token string">'city:'</span><span class="token punctuation">,</span> city<span class="token punctuation">)</span>
<span class="token comment">#按顺序提供默认参数，即7表示age的值 </span>
enroll<span class="token punctuation">(</span><span class="token string">'Bob'</span><span class="token punctuation">,</span> <span class="token string">'M'</span><span class="token punctuation">,</span> <span class="token number">7</span><span class="token punctuation">)</span>
<span class="token comment">#按参数名提供默认参数，即city值，而没有age的值</span>
enroll<span class="token punctuation">(</span><span class="token string">'Adam'</span><span class="token punctuation">,</span> <span class="token string">'M'</span><span class="token punctuation">,</span> city<span class="token operator">=</span><span class="token string">'Tianjin'</span><span class="token punctuation">)</span>
</code></pre>
<p><strong>注意事项</strong>：默认参数必须指向不可变对象，例如整数，字符串，<code>None</code>等。不能指向可变对象，例如list。</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#错误示例，默认参数为可变对象list</span>
add_end<span class="token punctuation">(</span>L<span class="token operator">=</span><span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">:</span>
L<span class="token punctuation">.</span>append<span class="token punctuation">(</span><span class="token string">'END'</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> L
<span class="token comment">#每次调用都会在list中添加元素 </span>
<span class="token operator">>></span><span class="token operator">></span> add_end<span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token punctuation">[</span><span class="token string">'END'</span><span class="token punctuation">]</span>
<span class="token operator">>></span><span class="token operator">></span> add_end<span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token punctuation">[</span><span class="token string">'END'</span><span class="token punctuation">,</span> <span class="token string">'END'</span><span class="token punctuation">]</span>
<span class="token operator">>></span><span class="token operator">></span> add_end<span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token punctuation">[</span><span class="token string">'END'</span><span class="token punctuation">,</span> <span class="token string">'END'</span><span class="token punctuation">,</span> <span class="token string">'END'</span><span class="token punctuation">]</span>
</code></pre>
<p>以上例子中，Python函数在定义的时候，默认参数<code>L</code>的值就被计算出来了，即<code>[]</code>，因为默认参数<code>L</code>也是一个变量，它指向对象<code>[]</code>，每次调用该函数，如果改变了<code>L</code>的内容，则下次调用时，默认参数的内容就变了，不再是函数定义时的<code>[]</code>了。</p>
<p>可改为指向<code>None</code>这个不可变对象来避免该问题。例如：</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#默认参数指向不可变对象None</span>
<span class="token keyword">def</span> <span class="token function">add_end</span><span class="token punctuation">(</span>L<span class="token operator">=</span><span class="token boolean">None</span><span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token keyword">if</span> L <span class="token keyword">is</span> <span class="token boolean">None</span><span class="token punctuation">:</span>
L <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token punctuation">]</span>
L<span class="token punctuation">.</span>append<span class="token punctuation">(</span><span class="token string">'END'</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> L
<span class="token comment">#每次调用恢复原默认值</span>
<span class="token operator">>></span><span class="token operator">></span> add_end<span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token punctuation">[</span><span class="token string">'END'</span><span class="token punctuation">]</span>
<span class="token operator">>></span><span class="token operator">></span> add_end<span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token punctuation">[</span><span class="token string">'END'</span><span class="token punctuation">]</span>
</code></pre>
<h2 id="33-可变参数">3.3 可变参数</h2>
<p>可变参数，即待传入的参数的个数是可变的，定义时在参数前面加个<code>*</code>，例如<code>*number</code>。可变参数在函数调用时实际上是一个tuple。</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#定义可变参数 *number</span>
<span class="token keyword">def</span> <span class="token function">calc</span><span class="token punctuation">(</span><span class="token operator">*</span>numbers<span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token builtin">sum</span> <span class="token operator">=</span> <span class="token number">0</span>
<span class="token keyword">for</span> n <span class="token keyword">in</span> numbers<span class="token punctuation">:</span>
<span class="token builtin">sum</span> <span class="token operator">=</span> <span class="token builtin">sum</span> <span class="token operator">+</span> n <span class="token operator">*</span> n
<span class="token keyword">return</span> <span class="token builtin">sum</span>
<span class="token comment">#函数调用</span>
<span class="token operator">>></span><span class="token operator">></span> calc<span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">)</span>
<span class="token number">5</span>
<span class="token operator">>></span><span class="token operator">></span> calc<span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token number">0</span>
<span class="token comment">#已存在list待传入</span>
<span class="token operator">>></span><span class="token operator">></span> nums <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">]</span>
<span class="token operator">>></span><span class="token operator">></span> calc<span class="token punctuation">(</span>nums<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span><span class="token punctuation">,</span> nums<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span><span class="token punctuation">,</span> nums<span class="token punctuation">[</span><span class="token number">2</span><span class="token punctuation">]</span><span class="token punctuation">)</span>
<span class="token number">14</span>
<span class="token comment">#通过list方式出传入可变参数</span>
<span class="token operator">>></span><span class="token operator">></span> nums <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">]</span>
<span class="token operator">>></span><span class="token operator">></span> calc<span class="token punctuation">(</span><span class="token operator">*</span>nums<span class="token punctuation">)</span>
<span class="token number">14</span>
</code></pre>
<h2 id="34-关键字参数">3.4 关键字参数</h2>
<p>关键字参数，即可以传入0个或任意个含参数名的参数，关键字参数在函数调用时实际上是一个dict。</p>
<p>关键参数定义时在参数前面加<code>**</code>，例如<code>**kw</code>。</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#定义关键字参数</span>
<span class="token keyword">def</span> <span class="token function">person</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> age<span class="token punctuation">,</span> <span class="token operator">**</span>kw<span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token keyword">print</span><span class="token punctuation">(</span><span class="token string">'name:'</span><span class="token punctuation">,</span> name<span class="token punctuation">,</span> <span class="token string">'age:'</span><span class="token punctuation">,</span> age<span class="token punctuation">,</span> <span class="token string">'other:'</span><span class="token punctuation">,</span> kw<span class="token punctuation">)</span>
<span class="token comment">#传入必选参数</span>
<span class="token operator">>></span><span class="token operator">></span> person<span class="token punctuation">(</span><span class="token string">'Michael'</span><span class="token punctuation">,</span> <span class="token number">30</span><span class="token punctuation">)</span>
name<span class="token punctuation">:</span> Michael age<span class="token punctuation">:</span> <span class="token number">30</span> other<span class="token punctuation">:</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
<span class="token comment">#传入可选的关键字参数</span>
<span class="token operator">>></span><span class="token operator">></span> person<span class="token punctuation">(</span><span class="token string">'Adam'</span><span class="token punctuation">,</span> <span class="token number">45</span><span class="token punctuation">,</span> gender<span class="token operator">=</span><span class="token string">'M'</span><span class="token punctuation">,</span> job<span class="token operator">=</span><span class="token string">'Engineer'</span><span class="token punctuation">)</span>
name<span class="token punctuation">:</span> Adam age<span class="token punctuation">:</span> <span class="token number">45</span> other<span class="token punctuation">:</span> <span class="token punctuation">{</span><span class="token string">'gender'</span><span class="token punctuation">:</span> <span class="token string">'M'</span><span class="token punctuation">,</span> <span class="token string">'job'</span><span class="token punctuation">:</span> <span class="token string">'Engineer'</span><span class="token punctuation">}</span>
<span class="token comment">#使用dict方式传入关键字参数</span>
<span class="token operator">>></span><span class="token operator">></span> extra <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">'city'</span><span class="token punctuation">:</span> <span class="token string">'Beijing'</span><span class="token punctuation">,</span> <span class="token string">'job'</span><span class="token punctuation">:</span> <span class="token string">'Engineer'</span><span class="token punctuation">}</span>
<span class="token operator">>></span><span class="token operator">></span> person<span class="token punctuation">(</span><span class="token string">'Jack'</span><span class="token punctuation">,</span> <span class="token number">24</span><span class="token punctuation">,</span> <span class="token operator">**</span>extra<span class="token punctuation">)</span>
name<span class="token punctuation">:</span> Jack age<span class="token punctuation">:</span> <span class="token number">24</span> other<span class="token punctuation">:</span> <span class="token punctuation">{</span><span class="token string">'city'</span><span class="token punctuation">:</span> <span class="token string">'Beijing'</span><span class="token punctuation">,</span> <span class="token string">'job'</span><span class="token punctuation">:</span> <span class="token string">'Engineer'</span><span class="token punctuation">}</span>
</code></pre>
<p>通过dict方式传入实际上是传入一份拷贝，函数参数的改变并不会影响到函数外原dict的值。</p>
<h2 id="35-命名关键字参数">3.5 命名关键字参数</h2>
<p>通过对关键字参数命名的方式限制只能传入指定名字的关键字参数，而不能传入其他参数。命名关键字参数需要一个特殊分隔符<code>*</code>，<code>*</code>后面的参数被视为命名关键字参数。例如：</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#定义命名关键字参数</span>
<span class="token keyword">def</span> <span class="token function">person</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> age<span class="token punctuation">,</span> <span class="token operator">*</span><span class="token punctuation">,</span> city<span class="token punctuation">,</span> job<span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token keyword">print</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> age<span class="token punctuation">,</span> city<span class="token punctuation">,</span> job<span class="token punctuation">)</span>
<span class="token comment">#命名关键字参数的调用 </span>
<span class="token operator">>></span><span class="token operator">></span> person<span class="token punctuation">(</span><span class="token string">'Jack'</span><span class="token punctuation">,</span> <span class="token number">24</span><span class="token punctuation">,</span> city<span class="token operator">=</span><span class="token string">'Beijing'</span><span class="token punctuation">,</span> job<span class="token operator">=</span><span class="token string">'Engineer'</span><span class="token punctuation">)</span>
Jack <span class="token number">24</span> Beijing Engineer
</code></pre>
<p>命名关键字参数必须传入参数名，如果没有传入参数名，调用将报错。</p>
<pre class="language-"><code class="lang-python"><span class="token operator">>></span><span class="token operator">></span> person<span class="token punctuation">(</span><span class="token string">'Jack'</span><span class="token punctuation">,</span> <span class="token number">24</span><span class="token punctuation">,</span> <span class="token string">'Beijing'</span><span class="token punctuation">,</span> <span class="token string">'Engineer'</span><span class="token punctuation">)</span>
Traceback <span class="token punctuation">(</span>most recent call last<span class="token punctuation">)</span><span class="token punctuation">:</span>
File <span class="token string">"<stdin>"</span><span class="token punctuation">,</span> line <span class="token number">1</span><span class="token punctuation">,</span> <span class="token keyword">in</span> <span class="token operator"><</span>module<span class="token operator">></span>
TypeError<span class="token punctuation">:</span> person<span class="token punctuation">(</span><span class="token punctuation">)</span> takes <span class="token number">2</span> positional arguments but <span class="token number">4</span> were given
</code></pre>
<p>命名关键字参数可以有缺省值，即默认参数。</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#命名关键字参数的缺省值</span>
<span class="token keyword">def</span> <span class="token function">person</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> age<span class="token punctuation">,</span> <span class="token operator">*</span><span class="token punctuation">,</span> city<span class="token operator">=</span><span class="token string">'Beijing'</span><span class="token punctuation">,</span> job<span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token keyword">print</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> age<span class="token punctuation">,</span> city<span class="token punctuation">,</span> job<span class="token punctuation">)</span>
<span class="token comment">#函数调用</span>
<span class="token operator">>></span><span class="token operator">></span> person<span class="token punctuation">(</span><span class="token string">'Jack'</span><span class="token punctuation">,</span> <span class="token number">24</span><span class="token punctuation">,</span> job<span class="token operator">=</span><span class="token string">'Engineer'</span><span class="token punctuation">)</span>
Jack <span class="token number">24</span> Beijing Engineer
</code></pre>
<h2 id="36-参数组合">3.6 参数组合</h2>
<p>必选参数、默认参数、可变参数、关键字参数和命名关键字参数，这5种参数可以组合使用。但参数定义的顺序必须是：必选参数、默认参数、可变参数、命名关键字参数和关键字参数。</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#参数组合的定义</span>
<span class="token keyword">def</span> <span class="token function">f1</span><span class="token punctuation">(</span>a<span class="token punctuation">,</span> b<span class="token punctuation">,</span> c<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token operator">*</span>args<span class="token punctuation">,</span> <span class="token operator">**</span>kw<span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token keyword">print</span><span class="token punctuation">(</span><span class="token string">'a ='</span><span class="token punctuation">,</span> a<span class="token punctuation">,</span> <span class="token string">'b ='</span><span class="token punctuation">,</span> b<span class="token punctuation">,</span> <span class="token string">'c ='</span><span class="token punctuation">,</span> c<span class="token punctuation">,</span> <span class="token string">'args ='</span><span class="token punctuation">,</span> args<span class="token punctuation">,</span> <span class="token string">'kw ='</span><span class="token punctuation">,</span> kw<span class="token punctuation">)</span>
<span class="token keyword">def</span> <span class="token function">f2</span><span class="token punctuation">(</span>a<span class="token punctuation">,</span> b<span class="token punctuation">,</span> c<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token operator">*</span><span class="token punctuation">,</span> d<span class="token punctuation">,</span> <span class="token operator">**</span>kw<span class="token punctuation">)</span><span class="token punctuation">:</span>
<span class="token keyword">print</span><span class="token punctuation">(</span><span class="token string">'a ='</span><span class="token punctuation">,</span> a<span class="token punctuation">,</span> <span class="token string">'b ='</span><span class="token punctuation">,</span> b<span class="token punctuation">,</span> <span class="token string">'c ='</span><span class="token punctuation">,</span> c<span class="token punctuation">,</span> <span class="token string">'d ='</span><span class="token punctuation">,</span> d<span class="token punctuation">,</span> <span class="token string">'kw ='</span><span class="token punctuation">,</span> kw<span class="token punctuation">)</span>
<span class="token comment">#参数组合的调用</span>
<span class="token operator">>></span><span class="token operator">></span> f1<span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token string">'a'</span><span class="token punctuation">,</span> <span class="token string">'b'</span><span class="token punctuation">,</span> x<span class="token operator">=</span><span class="token number">99</span><span class="token punctuation">)</span>
a <span class="token operator">=</span> <span class="token number">1</span> b <span class="token operator">=</span> <span class="token number">2</span> c <span class="token operator">=</span> <span class="token number">3</span> args <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token string">'a'</span><span class="token punctuation">,</span> <span class="token string">'b'</span><span class="token punctuation">)</span> kw <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">'x'</span><span class="token punctuation">:</span> <span class="token number">99</span><span class="token punctuation">}</span>
<span class="token operator">>></span><span class="token operator">></span> f2<span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> d<span class="token operator">=</span><span class="token number">99</span><span class="token punctuation">,</span> ext<span class="token operator">=</span><span class="token boolean">None</span><span class="token punctuation">)</span>
a <span class="token operator">=</span> <span class="token number">1</span> b <span class="token operator">=</span> <span class="token number">2</span> c <span class="token operator">=</span> <span class="token number">0</span> d <span class="token operator">=</span> <span class="token number">99</span> kw <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">'ext'</span><span class="token punctuation">:</span> <span class="token boolean">None</span><span class="token punctuation">}</span>
</code></pre>
<p>通过tuple和dict调用参数组合函数：</p>
<pre class="language-"><code class="lang-python"><span class="token comment">#f1</span>
<span class="token operator">>></span><span class="token operator">></span> args <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">)</span>
<span class="token operator">>></span><span class="token operator">></span> kw <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">'d'</span><span class="token punctuation">:</span> <span class="token number">99</span><span class="token punctuation">,</span> <span class="token string">'x'</span><span class="token punctuation">:</span> <span class="token string">'#'</span><span class="token punctuation">}</span>
<span class="token operator">>></span><span class="token operator">></span> f1<span class="token punctuation">(</span><span class="token operator">*</span>args<span class="token punctuation">,</span> <span class="token operator">**</span>kw<span class="token punctuation">)</span>
a <span class="token operator">=</span> <span class="token number">1</span> b <span class="token operator">=</span> <span class="token number">2</span> c <span class="token operator">=</span> <span class="token number">3</span> args <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token number">4</span><span class="token punctuation">,</span><span class="token punctuation">)</span> kw <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">'d'</span><span class="token punctuation">:</span> <span class="token number">99</span><span class="token punctuation">,</span> <span class="token string">'x'</span><span class="token punctuation">:</span> <span class="token string">'#'</span><span class="token punctuation">}</span>
<span class="token comment">#f2</span>
<span class="token operator">>></span><span class="token operator">></span> args <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">)</span>
<span class="token operator">>></span><span class="token operator">></span> kw <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">'d'</span><span class="token punctuation">:</span> <span class="token number">88</span><span class="token punctuation">,</span> <span class="token string">'x'</span><span class="token punctuation">:</span> <span class="token string">'#'</span><span class="token punctuation">}</span>
<span class="token operator">>></span><span class="token operator">></span> f2<span class="token punctuation">(</span><span class="token operator">*</span>args<span class="token punctuation">,</span> <span class="token operator">**</span>kw<span class="token punctuation">)</span>
a <span class="token operator">=</span> <span class="token number">1</span> b <span class="token operator">=</span> <span class="token number">2</span> c <span class="token operator">=</span> <span class="token number">3</span> d <span class="token operator">=</span> <span class="token number">88</span> kw <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">'x'</span><span class="token punctuation">:</span> <span class="token string">'#'</span><span class="token punctuation">}</span>
</code></pre>
<p>对于任意函数，都可以通过类似<code>func(*args, **kw)</code>的形式调用它，无论它的参数是如何定义的。</p>
<p>参考：</p>
<ul>
<li><a href="https://www.liaoxuefeng.com/wiki/1016959663602400/1017261630425888" target="_blank">https://www.liaoxuefeng.com/wiki/1016959663602400/1017261630425888</a> </li>
</ul>
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