列表是什么?
列表由一些列按照特定顺序排列而成的元素。
在Python中,由[]表示列表,并用“,”分隔开其中的元素
1 2
| bicycle = ['trek','cannondale','redline'] print(bicycle)
|
这样的话会打印
1
| ['trek','cannondale','redline']
|
没错,他会连着【】一块打印下来,没想到吧
访问列表元素
列表式有序集合,所以要访问列表式只需要将该元素的索引告诉Python就好。
例如
1 2
| bicycle = ['trek','cannondale','redline'] print(bicycle[0])
|
当你请求访问列表元素时,Python只会返回该元素,而不包括【】
当然你也可以使用之前学习过的方法
1 2
| bicycle = ['trek','cannondale','redline'] print(bicycle[0].title())
|
这样的话会输出
值得一提的是
索引是从0开始而并不是1开始
在Python中,第一个列表元素的索引为0而不是1.(这一点 就跟C语言的数组那块一样,都是从0开始的)
1 2 3
| bicycle = ['trek','cannondale','redline'] print(bicycle[1]) print(bicycle[2])
|
当你想要倒过来访问列表的时候,Python会提供给你一种特殊的语法。通过将索引定位为-1,可让Python返回最后一个列表元素:
1 2
| bicycle = ['trek','cannondale','redline'] print(bicycle[-1])
|
修改添加和删除元素
修改
很简单,用索引定位就好
1 2 3 4
| bicycle = ['trek','cannondale','redline'] print(bicycle) bicycle[0] = 'baba' print(bicycle)
|
1 2
| ['trek','cannondale','redline'] ['baba','cannondale','redline']
|
添加
在列表未添加元素
这是一个很神奇的东西,他可以让你在列表的末尾添加元素
1 2 3 4
| bicycle = ['trek','cannondale','redline'] print(bicycle) bicycle.append = ('ca') print(bicycle)
|
1 2
| 'trek','cannondale','redline' 'trek','cannondale','redline''ca'
|
当然,如果你足够闲得无聊,你也来可以尝试
1 2 3 4 5 6 7
| name = [] name.append=('zgh') nmae.append=('cjy') nmae.append=('czm') nmae.append=('dyf') nmae.append=('czh') print(name)
|
1
| ['cgh','cjy','czm','dlf','czh']
|
有了在末尾添加当然就有在中间添加了
1 2 3 4
| bicycle = ['trek','cannondale','redline'] print(bicycle) bicycle.insect = (1,'ca') print(bicycle)
|
1 2
| 'trek','cannondale','redline' 'trek','ca','cannondale','redline'
|
删除
1 2 3 4
| bicycle = ['trek','cannondale','redline'] print(bicycle) del bicycle[0] print(bicycle)
|
1 2
| 'trek','cannondale','redline' 'cannondale','redline'
|
使用del可以无线删除,当然,前提是你知道这个元素在Python中的索引值
当然你也可以使用方法pop()删除
(我感觉这个列表就像一个栈,pop使用就像弹出这个栈顶)
1 2 3 4 5 6
| bicycle = ['trek','cannondale','redline'] print(bicycle) outdate = bicycle.pop() print(bicycle) print(outdate) (这一块本来我打算用popped的,但@一般路过小辉夜给了更好的建议,所以就用outdata了)
|
1 2 3
| 'trek','cannondale','redline' ‘trek’'cannondale' 'redline'
|
弹出任何位置的元素
其实吧,pop这个东西不知能删除最后一个元素,你只要在括号里面填写你想要的元素的索引,他都能给你弹出来
1 2 3 4 5
| bicycle = ['trek','cannondale','redline'] print(bicycle) outdate = bicycle.pop(1) print(bicycle) print(outdate)
|
1 2 3
| 'trek','cannondale','redline' 'trek,'redline' 'cannondale'
|
需要注意的是,当你弹出元素的时候,这个元素就不在列表中了
根据特定的值删除
1 2 3 4
| bicycle = ['trek','cannondale','redline'] print(bicycle) bicycle.remove('cannondale') print(bicycle)
|
1 2
| ['trek','cannondale','redline'] ['trek',redline']
|
使用remove的时候也可以照常使用这个值
1 2 3 4 5
| bicycle = ['trek','cannondale','redline'] print(bicycle) abb = 'cannondale' bicycle.remove('cannondale') print(f"{abb.title()}")
|
1 2
| ['trek', 'cannondale', 'redline'] Cannondale
|
组织列表
sort()
使用sort()可以将列表进行用就行排序(这个是按照字母进行排序的)
1 2 3
| bicycle = ['trek','cannondale','redline'] bicycle.sort() print(bicycle)
|
1
| ['cannondale','redline','trek']
|
当你要逆字母方向时,需要
1 2 3
| bicycle = ['trek','cannondale','redline'] bicycle.sort(reverse = True) print(bicycle)
|
1
| ['trek', 'redline', 'cannondale']
|
使用sorted函数进行临时性的排序
1 2 3 4
| bicycle = ['trek','cannondale','redline'] print(bicycle) print(sorted(bicycle)) print(bicycle)
|
1 2 3
| ['trek', 'cannondale', 'redline'] ['cannondale', 'redline', 'trek'] ['trek', 'cannondale', 'redline']
|
倒着打印列表
1 2 3 4
| bicycle = ['trek','cannondale','redline'] print(bicycle) bicycle.reverse() print(bicycle)
|
1 2
| ['trek', 'cannondale', 'redline'] ['redline', 'cannondale', 'trek']
|
确定列表长度
1 2 3
| >>>bicycle = ['trek','cannondale','redline'] >>>len(bicycle) 3
|