擅长:python、mysql、java
<p>您可以使用默认dict</p>
<pre class="lang-py prettyprint-override"><code>from collections import defaultdict
d = defaultdict(lambda : 'xx') #<- Whatever value you want
d[10] #no value passed value automatically assinged to xx
d[11]=12 #value 12 assinged
#to get value you can use d.get(key)
print(d[10]) #prints 'xx'
print(d)
</code></pre>
<p>输出</p>
<pre><code>defaultdict(<function <lambda> at 0x000001557B4B03A8>, {10: 'xx', 11: 12})
</code></pre>
<p>您可以根据需要进行修改</p>