blocks|key|1345263|text|就地清除列表将影响同一列表的所有其他引用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1345264|例如，此方法不会影响其他引用：|1345265|>>>+a+=+[1,+2,+3]
>>>+b+=+a
>>>+a+=+[]
>>>+print(a)
[]
>>>+print(b)
[1,+2,+3]|code-block|syntax|javascript|1345266|但这一条是：|1345267|>>>+a+=+[1,+2,+3]
>>>+b+=+a
>>>+del+a[:]++++++#+equivalent+to+++del+a[0:len(a)]
>>>+print(a)
[]
>>>+print(b)
[]
>>>+a+is+b
True|1345268|您还可以执行以下操作：|1345269|>>>+a[:]+=+[]|1345270|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

Clearing a list in place will affect all other references of the same list.

For example, this method doesn't affect other references:

<pre><code>&gt;&gt;&gt; a = [1, 2, 3]
&gt;&gt;&gt; b = a
&gt;&gt;&gt; a = []
&gt;&gt;&gt; print(a)
[]
&gt;&gt;&gt; print(b)
[1, 2, 3]
</code></pre>

But this one does:

<pre><code>&gt;&gt;&gt; a = [1, 2, 3]
&gt;&gt;&gt; b = a
&gt;&gt;&gt; del a[:] # equivalent to del a[0:len(a)]
&gt;&gt;&gt; print(a)
[]
&gt;&gt;&gt; print(b)
[]
&gt;&gt;&gt; a is b
True
</code></pre>

You could also do:

<pre><code>&gt;&gt;&gt; a[:] = []
</code></pre>

blocks|key|1560840|text|del+list[:]+|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1560841|将删除该列表变量的值|unstyled|1560842|del+list|1560843|将从内存中删除变量本身|1560844|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code>del list[:] 
</code></pre>

Will delete the values of that list variable 

<pre><code>del list
</code></pre>

Will delete the variable itself from memory

blocks|key|1560864|text|如果你正在清空列表，显然，你不再需要这个列表了。如果是这样的话，你可以通过简单的del方法删除整个列表。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1560865|a+=+[1,+3,+5,+6]
del+a+#+This+will+entirely+delete+a(the+list).|code-block|syntax|javascript|1560866|但是，如果您再次需要它，您可以重新初始化它。或者只是简单地通过以下方式清除其元素|1560867|del+a[:]|1560868|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you're clearing the list, you, obviously, don't need the list anymore. If so, you can just delete the entire list by simple del method.

<pre><code>a = [1, 3, 5, 6]
del a # This will entirely delete a(the list).
</code></pre>

But in case, you need it again, you can reinitialize it. Or just simply clear its elements by 

<pre><code>del a[:]
</code></pre>

blocks|key|1560910|text|另一个有效的解决方案是创建空列表作为引用空列表。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1560911|empt_list+=+[]|code-block|syntax|javascript|1560912|例如，您有一个a_list+=+[1,2,3]形式的列表。要清除它，只需执行以下操作：|offset|length|style|CODE|1560913|a_list+=+list(empt_list)|1560914|这将使a_list成为一个与empt_list一样的空列表。|1560915|entityMap^0|0|0|7|G|0|0|3|6|E|9|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@$I|V|J|W|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|Y|8|@$I|Z|J|10|K|L]|$I|11|J|12|K|L]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|13|8|@]|9|@]|A|$]]]|R|$]]

another solution that works fine is to create empty list as a reference empty list.

<pre><code>empt_list = []
</code></pre>

for example you have a list as <code>a_list = [1,2,3]</code>. To clear it just make the following:

<pre><code>a_list = list(empt_list)
</code></pre>

this will make <code>a_list</code> an empty list just like the <code>empt_list</code>.

Is there any reason to do anything more complicated than one of these two lines when you want to clear a list in Python?

<pre><code>old_list = []
old_list = list()
</code></pre>

The reason I ask is that I just saw this in some running code:

<pre><code>del old_list[ 0:len(old_list) ]
</code></pre>

Different ways of clearing lists

Python

当您想要在Python中清除列表时，有没有理由做比这两行中的一行更复杂的事情呢？old_list = []old_list = list()我这么问的原因是我在一些运行代码中看到了这一点：del old_list[ 0:len(old_list) ]

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