列表的常用操作和内置方法
1、用途:
按照索引存放多个任意类型的值,索引反映的是位置/顺序
2、定义方式:
在[]内用逗号分割开多个任意类型的元素
l=[111,1.1,"aaa",[2222,3333]] # l=list([111,1.1,"aaa",[2222,3333]])
print(type(l))
数据类型转换:
res=list("hello")
res=list({"k1":1,"k2":2,"k3":3})
print(res)
3、常用操作+内置的方法
优先掌握的操作:
l1 = [11,22,33,44,55]
print(l1[0])
print(l1[10])
print(l1[-1])
print(id(l1))
l1[0] = 100
print(id(l1))
l1[5] = 11111
d = {'k1':2}
d['kkkk']=22222
print(d)
l1 = [11,22,[66,77]]
res=l1[2:4]
print(res)
print(l1)
l2=l1[:]
l2=l1.copy()
print(id(l1[0]),id(l1[1]),id(l1[2]))
print(id(l2[0]),id(l2[1]),id(l2[2]))
l1[0] = "aaa"
l1[1] = "bbb"
l1[2] = "ccc"
l1[2][0] = 8888
print(l2)
from copy import deepcopy
l3=deepcopy(l1)
print(id(l3[0]),id(l3[1]),id(l3[2]))
l1[2][0]=6666
print(l1)
print(l3)
l1[0]=1000
print(l1)
print(l2)
l1[-1][0]=666
print(l1)
res=l1[-1:-4:-1]
res=l1[::-1]
print(res)
l1 = [11,22,[66,77]]
print(len(l1))
l1 = [111,22,[66,77]]
print([66,77] in l1)
print(66 in l1)
print(66 not in l1)
l1=[11,222]
l1.append(33)
l1.append(44)
l1.append([55,66])
print(l1)
l1.insert(1,"aaa")
print(l1)
l1=[11,222,[1,2]]
del l1[0]
print(l1)
res=l1.remove([1,2])
print(l1)
print(res)
res=l1.pop(1)
print(l1)
print(res)
l1=[11,222,[1,2]]
for x in l1:
print(x)
需要掌握的操作:
l1=[11,22,333,333,333,]
l1.extend("hello")
print(l1)
需要掌握的操作:
需要掌握的操作:
l1=[11,22,333,333,333,]
l1.extend("hello")
print(l1)
总结:
"""
# 存一个值or存多个值
# 有序or无序
# 可变or不可变(1、可变:值变,id不变。可变==不可hash 2、不可变:值变,id就变。不可变==可hash)
"""