python: extend(),append(),insert()

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三者皆可添加元素

建立两个list a,b

append()接受一个对象参数，把对象添加到列表的尾部

>>> a
[1, 2, 3]
>>> b
[4, 5, 6]
>>> a.append(77)
>>> a
[1, 2, 3, 77]
>>> a.append('good')
>>> a
[1, 2, 3, 77, 'good']


>>> a
[1, 2, 3, 7, '7', [4, 5, 6]]

extend()接受一个列表参数，把参数列表的元素添加到列表的尾

>>> a = [1,2,3]
>>> a.extend('good')
>>> a
[1, 2, 3, 'g', 'o', 'o', 'd']
>>> a.extend(b)
>>> a
[1, 2, 3, 'g', 'o', 'o', 'd', 4, 5, 6]

insert( index, object ) index要插入的位置，object 要插入的对象

>>> a
[1, 4, 2, 3]
>>> a.insert(1,[4,5])
>>> a
[1, [4, 5], 4, 2, 3]
>>> a.insert(1,'good')
>>> a
[1, 'good', [4, 5], 4, 2, 3]