Python常用列表数据结构小结

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Release: 2016-06-16 08:43:01
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本文汇总了Python列表list一些常用的对象方法,可供初学者参考或查询,具体如下:

1.list.append(x)

把元素x添加到列表的结尾,相当于a[len(a):] =[x],代码如下:

>>> a=[1,2,3,4,5]
>>> a
[1, 2, 3, 4, 5]
>>> a.append(-2)
>>> a
[1, 2, 3, 4, 5, -2]

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2. list.extend(L)

将一个列表中的所有元素都添加到另一个列表中,相当于 a[len(a):] = L,代码如下:

>>> a
[1, 2, 3, 4, 5, -2]
>>> L=[5,9,7]
>>> L
[5, 9, 7]
>>> a.extend(L)
>>> a
[1, 2, 3, 4, 5, -2, 5, 9, 7]

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3. list.insert(i,x)

将元素x,插到索引号i之前,代码如下:

>>> a
[1, 2, 3, 4, 5, -2, 5, 9, 7]
>>> a.insert(0,-3)
>>> a
[-3, 1, 2, 3, 4, 5, -2, 5, 9, 7]
>>> a.insert(len(a),10)
>>> a
[-3, 1, 2, 3, 4, 5, -2, 5, 9, 7, 10]

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4. list.remove(x)

删除元素x(第一次出现的),代码如下:

>>> a
[-3, 1, 2, 3, 4, 5, -2, 5, 9, 7, 10]
>>> a.append(1)
>>> a
[-3, 1, 2, 3, 4, 5, -2, 5, 9, 7, 10, 1]
>>> a.remove(1)
>>> a
[-3, 2, 3, 4, 5, -2, 5, 9, 7, 10, 1]

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5. list.count(x)

计算元素x出现的次数,代码如下:

>>> a
[-3, 2, 3, 4, 5, -2, 5, 9, 7, 10, 1]
>>> a.count(3)
1
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6. list.sort()

对列表元素进行排序,代码如下:

>>> a.sort()
>>> a
[-3, -2, 1, 2, 3, 4, 5, 5, 7, 9, 10]
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7. list.reverse()

倒排列表中元素,代码如下:

>>> a
[-3, -2, 1, 2, 3, 4, 5, 5, 7, 9, 10]
>>> a.reverse()
>>> a
[10, 9, 7, 5, 5, 4, 3, 2, 1, -2, -3]
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8. list.index(x)

返回表中第一个出现值为x的索引,代码如下:

>>> a
[10, 9, 7, 5, 5, 4, 3, 2, 1, -2, -3]
>>> a.index(9)
1
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9. list.pop(i)

从列表指定位置i删除元素,并将此元素返回,若未指定位置则删除列表最后一位元素,并将此元素返回。代码如下:

>>> a
[10, 9, 7, 5, 5, 4, 3, 2, 1, -2, -3]
>>> a.pop(0)
10
>>> a
[9, 7, 5, 5, 4, 3, 2, 1, -2, -3]
>>> a.pop()
-3
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