擅长:python、mysql、java
<p>读一下这个<a href="https://docs.python.org/3/tutorial/datastructures.html#sets" rel="nofollow noreferrer">documentation</a></p>
<p>集合是无序集合</p>
<p>您可以使用其他模块,如<a href="https://docs.python.org/3/library/collections.html#collections.OrderedDict" rel="nofollow noreferrer">OrderedDict</a></p>
<pre><code>from collections import OrderedDict
od = OrderedDict()
od['a'] = 1
od['b'] = 2
od['c'] = 3
od['d'] = 4
for key, value in od.items():
print(key, value)
</code></pre>
<p>输出:</p>
<pre><code>('a', 1)
('b', 2)
('c', 3)
('d', 4)
</code></pre>