在python中,用方括号表示列表,元素之间用逗号分隔开。是个可变长序列,可以进行增删改操作。
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles[0])
trek
注意列表的索引是从0开始的。python为访问最后一个元素提供了一种特殊的语法,可以使用索引为-1,同理,若想访问倒数第2个元素,索引为-2
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles[-1])
specialized
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
bicycles[2] = 'train'
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
['trek', 'cannondale', 'train', 'specialized']
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
bicycles.append('ducati')
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
['trek', 'cannondale', 'redline', 'specialized', 'ducati']
在调用函数时,不仅需要添加的元素,还有要添加的位置
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
bicycles.insert(0,'ducati')
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
['ducati', 'trek', 'cannondale', 'redline', 'specialized']
需要指明需要删除元素的位置,当把元素从列表中删除后,就再也无法使用它了。
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
del bicycles[-1]
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
['trek', 'cannondale', 'redline']
使用pop()可以删除列表中指定位置的元素,只需要在括号中指明删除元素的索引,另外可以访问被删除的值
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
bicycle = bicycles.pop(-1)
print(bicycle)
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
specialized
['trek', 'cannondale', 'redline']
用remove()函数
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
bicycles.remove('redline')
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
['trek', 'cannondale', 'specialized']
bicycles = ['trek','cannondale','redline','specialized']
bicycles.sort()
print(bicycles)
['cannondale', 'redline', 'specialized', 'trek']
可以看出使用sort()函数,将列表按照首字母顺序进行排序,并且是永久性的
bicycles.sort(reverse=True)
['trek', 'specialized', 'redline', 'cannondale']
也可以通过此种方法来按照字母顺序相反来排序,且为永久性更改
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
print(sorted(bicycles))
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
['cannondale', 'redline', 'specialized', 'trek']
['trek', 'cannondale', 'redline', 'specialized']
bicycles = ['trek','cannondale','redline','specialized']
print(bicycles)
bicycles.reverse()
print(bicycles)
['trek', 'cannondale', 'redline', 'specialized']
['specialized', 'redline', 'cannondale', 'trek']
是永久性的更改
bicycles = ['trek','cannondale','redline','specialized']
print(len(bicycles))
4