您好,欢迎访问一九零五行业门户网

python基础-list

1、list创建
new_list1 = ['tv','car','cloth','food']
new_list2 = list(['tv','car','cloth','food'])
print (new_list1)
print (new_list2)
运行结果:
['tv', 'car', 'cloth', 'food']
['tv', 'car', 'cloth', 'food']
2、list常用的方法:
 1. append
new_list1 = ['tv','car','cloth','food']
print (new_list1)
new_list1.append('water') #追加'water'
print (new_list1)   
运行结果:
['tv', 'car', 'cloth', 'food']
['tv', 'car', 'cloth', 'food', 'water']
2.count
new_list1 = ['tv','car','cloth','food','food']
print (new_list1.count('food')) #统计'food'在列表中的次数 => 2次
3.extend
new_list1 = ['tv','car','cloth','food','food']
new_list1.extend([11,22,33,'car'])
print (new_list1)   
运行结果:
['tv', 'car', 'cloth', 'food', 'food', 11, 22, 33, 'car']
4.sort
new_list1 = ['tv','car','cloth','food','food']
print (new_list1)
new_list1.sort() #正向排序
print (new_list1)
new_list1.sort(reverse=true) #反向排序
print (new_list1)   
运行结果:
['tv', 'car', 'cloth', 'food', 'food']
['car', 'cloth', 'food', 'food', 'tv'] #正向排序结果
['tv', 'food', 'food', 'cloth', 'car'] #反向排序结果
5. len
new_list1 = ['tv','car','food','cloth','food']
print (len(new_list1)) => 5 #打印元素的个数
6.remove
new_list1 = ['tv','car','food','cloth','food']
new_list1.remove('food')
print (new_list1)
运行结果:
['tv', 'car', 'cloth', 'food'] #remove会删除找到的第一个相同元素
7.pop
new_list1 = ['tv','car','food','cloth','food']
new_list1.pop() #随机删除一个元素
print (new_list1)
new_list1.pop(2) #指定删除某个元素
print (new_list1)
运行结果为:
['tv', 'car', 'food', 'cloth']
['tv', 'car', 'cloth'] #,此处删除的是第3个元素'food'
8.index
new_list1 = ['tv','car','food','cloth','food']
print (new_list1.index('food')) #返回指定元素的index值,相同元素返回查找到的第一个
运行结果为:2
9.insert
new_list1 = ['tv','car','food','cloth','food']
new_list1.insert(2,'hahaha')  #向指定的位置插入元素
print (new_list1)
运行结果为:
['tv', 'car', 'hahaha', 'food', 'cloth', 'food']
其它类似信息

推荐信息