字典内置函数&方法

╰半夏微凉° 2022-05-20 10:30 304阅读 0赞

<table> 
 <tbody> 
  <tr> 
   <th>序号</th> 
   <th>函数及描述</th> 
  </tr> 
  <tr> 
   <td>1</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-cmp.html" rel="nofollow">cmp(dict1, dict2)</a><br> 比较两个字典元素。</td> 
  </tr> 
  <tr> 
   <td>2</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-len.html" rel="nofollow">len(dict)</a><br> 计算字典元素个数，即键的总数。</td> 
  </tr> 
  <tr> 
   <td>3</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-str.html" rel="nofollow">str(dict)</a><br> 输出字典可打印的字符串表示。</td> 
  </tr> 
  <tr> 
   <td>4</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-type.html" rel="nofollow">type(variable)</a><br> 返回输入的变量类型，如果变量是字典就返回字典类型。</td> 
  </tr> 
 </tbody> 
</table>

Python字典包含了以下内置方法：

<table> 
 <tbody> 
  <tr> 
   <th>序号</th> 
   <th>函数及描述</th> 
  </tr> 
  <tr> 
   <td>1</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-clear.html" rel="nofollow">dict.clear()</a><br> 删除字典内所有元素</td> 
  </tr> 
  <tr> 
   <td>2</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-copy.html" rel="nofollow">dict.copy()</a><br> 返回一个字典的浅复制</td> 
  </tr> 
  <tr> 
   <td>3</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-fromkeys.html" rel="nofollow">dict.fromkeys(seq[, val])</a><br> 创建一个新字典，以序列 seq 中元素做字典的键，val 为字典所有键对应的初始值</td> 
  </tr> 
  <tr> 
   <td>4</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-get.html" rel="nofollow">dict.get(key, default=None)</a><br> 返回指定键的值，如果值不在字典中返回default值</td> 
  </tr> 
  <tr> 
   <td>5</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-has_key.html" rel="nofollow">dict.has_key(key)</a><br> 如果键在字典dict里返回true，否则返回false</td> 
  </tr> 
  <tr> 
   <td>6</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-items.html" rel="nofollow">dict.items()</a><br> 以列表返回可遍历的(键, 值) 元组数组</td> 
  </tr> 
  <tr> 
   <td>7</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-keys.html" rel="nofollow">dict.keys()</a><br> 以列表返回一个字典所有的键</td> 
  </tr> 
  <tr> 
   <td>8</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-setdefault.html" rel="nofollow">dict.setdefault(key, default=None)</a><br> 和get()类似, 但如果键不存在于字典中，将会添加键并将值设为default</td> 
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  <tr> 
   <td>9</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-update.html" rel="nofollow">dict.update(dict2)</a><br> 把字典dict2的键/值对更新到dict里</td> 
  </tr> 
  <tr> 
   <td>10</td> 
   <td><a href="http://www.runoob.com/python/att-dictionary-values.html" rel="nofollow">dict.values()</a><br> 以列表返回字典中的所有值</td> 
  </tr> 
  <tr> 
   <td>11</td> 
   <td><a href="http://www.runoob.com/python/python-att-dictionary-pop.html" rel="nofollow">pop(key[,default])</a><br> 删除字典给定键 key 所对应的值，返回值为被删除的值。key值必须给出。 否则，返回default值。</td> 
  </tr> 
  <tr> 
   <td>12</td> 
   <td><a href="http://www.runoob.com/python/python-att-dictionary-popitem.html" rel="nofollow">popitem()</a><br> 随机返回并删除字典中的一对键和值。</td> 
  </tr> 
 </tbody> 
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