列表数据类型内置方法

列表数据类型内置方法

1.方法

描述多个值，比如爱好

2.定义方法

hobby_list = ['play','swimming','dancing','6666']

lt = list['nick']
print(lt)

3.内置方法

优先掌握

1. 索引取值

hobby_list = ['play','swimming','dancing','666']
print(hobby_list[-1])
hobby_list[-1] = '2333'		#索引修改
print(1,hobby_list[-1])

2. 切片

print(hobby_list[:])	 #全部取出
print(hobby_list[::-1])	 #-1代表从右到左输出

3. 长度

   print(len(hobby_list))
   hobby_list = ['play','swimming','dancing',666]
   

4. in / not in

hobby_list = ['play','swimming','dancing','666']
print('swimming' in hobby_list)		# True

5. for 循环

for hooby in hobby_list:
    print(hobby)

6. del 删除

del hobby_list[-1]
print(hobby_list)

7. append( ) # 追加

hobby_list = ['play','swimming','dancing','666']
hobby_list.append('23333')
print(hobby_list)

需要掌握

hobby_list = ['play','swimming','dancing','666']
print(hobby_list.count('666'))		#count() 计数
print(hobby_list.extend([1,2,3,4])) # 扩展列表  # Ctrl + 鼠标左键
print(hobby_list.clear())			# 清除

hobby_list2 = hobby_list.copy()  	#复制列表
print(hobby_list.pop())			 	#删除		默认删除最后一个
print(hobby_list.index('play',2,4))	#返回play的下标，或play是否在2~4的切片内
print(hobby_list.insert(0,'1'))		#插入
print(hobby_list.remove('1'))		#移除
print(hobby_list.reverse())			#反转
hpbby_list3 = [1,25,3,7,9]
print(hobby_list3.sort())			#排序

记住就行：

def func(i):
    return i[1]
print(hobby_list.sort())

4.存一个值还是多个值

多个值

5.有序or无序

有序

6.可变or不可变(重点)

可变