列表

列表的使用

从0开始计算，names[0] = "ZhangSan"     

names = ["ZhangSan","LiSi",["ZhaoQian,SunSan"],"WangWu"]

　特殊取值：顾头不顾尾name

names = ["ZhangSan","LiSi",["ZhaoQian,SunSan"],"WangWu"]
print(names[1:3])

结果：
['LiSi', ['ZhaoQian,SunSan']]

切片

names = ["ZhangSan","LiSi",["ZhaoQian,SunSan"],"WangWu"]
print(names[-1])#取最后一个
print(names[-2])#取倒数第二个

print(names[-2:])#取最后两个

• 增append()

names.append("ZhaoLiu") #在列表最后增加

　　

• insert():在列表的第四个位置，插入

names = ["ZhangSan","LiSi",["ZhaoQian,SunSan"],"WangWu"]
names.insert(3,"赵谦")
print(names)

#结果
['ZhangSan', 'LiSi', ['ZhaoQian,SunSan'], '赵谦', 'WangWu']

•  删除

names.remove("LiSi")#删除指定值
names.pop()#删除最后一个
names.pop(1)#删除第一个位置的内容
del names[1]#删除第一个位置的内容 ==names.pop(1)

del names  #删除整个列表

　　

• 查index()

　

names = ["ZhangSan","LiSi",["ZhaoQian,SunSan"],"WangWu"]
print(names.index("LiSi"))#查找LiSi所在位置
print(names[names.index("LiSi")])#根据查找所在位置后，获取LiSi

• count()

names = ["ZhangSan","LiSi",["ZhaoQian,SunSan"],"WangWu","LiSi"]
print(names.count('LiSi'))#查找列表中Lisi的数量

• clear()  清空列表内容
• reverse()   反转：将列表顺序变成从后到开始打印

names = ["ZhangSan","LiSi",["ZhaoQian,SunSan"],"WangWu","LiSi"]
print("反转前;",names)
names.reverse()
print("反转后：",names)

结果：
反转前; ['ZhangSan', 'LiSi', ['ZhaoQian,SunSan'], 'WangWu', 'LiSi']
反转后： ['LiSi', 'WangWu', ['ZhaoQian,SunSan'], 'LiSi', 'ZhangSan']

• sort()   排序：注意若列表里有列表，则不能使用

names = ["4ZhangSan","#LiSi","WangWu","LiSi"]
print("排序前;",names)
names.sort()
print("排序后：",names)

排序前; ['4ZhangSan', '#LiSi', 'WangWu', 'LiSi']
排序后： ['#LiSi', '4ZhangSan', 'LiSi', 'WangWu']

• extend() 合并：将两个列表合并

names = ["4ZhangSan","#LiSi","WangWu","LiSi"]
names2 = [1,2,3,4,]
names.extend(names2)
print(names)
print(names2)

结果:
['4ZhangSan', '#LiSi', 'WangWu', 'LiSi', 1, 2, 3, 4]
[1, 2, 3, 4]

• copy()   浅复制

names = ["ZhangSan","LiSi","WangWu","LiSi"]
names2 = names.copy()
print(names)
print(names2)
names2[2] = "李四"
print(names)
print(names2)


结果：
['ZhangSan', 'LiSi', 'WangWu', 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', 'LiSi']
['ZhangSan', 'LiSi', '李四', 'LiSi']

若列表包含列表的情况

names = ["ZhangSan","LiSi","WangWu",["alex","he","Hello"],"LiSi"]
names2 = names.copy()
print(names)
print(names2)
names2[3][1] = "李四"
print(names)
print(names2)

结果：
['ZhangSan', 'LiSi', 'WangWu', ['alex', 'he', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', 'he', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', '李四', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', '李四', 'Hello'], 'LiSi']

• import copy

导入copy里面的copy方法

import copy
names = ["ZhangSan","LiSi","WangWu",["alex","he","Hello"],"LiSi"]
names2 = copy.copy(names)
print(names)
print(names2)
names2[3][1] = "李四"
print(names)
print(names2)

结果：
['ZhangSan', 'LiSi', 'WangWu', ['alex', 'he', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', 'he', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', '李四', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', '李四', 'Hello'], 'LiSi']

导入copy里面的deepcopy()方法（这个尽量不使用）

import copy
names = ["ZhangSan","LiSi","WangWu",["alex","he","Hello"],"LiSi"]
names2 = copy.deepcopy(names)
print(names)
print(names2)
names2[3][1] = "李四"
print(names)
print(names2)

结果：
['ZhangSan', 'LiSi', 'WangWu', ['alex', 'he', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', 'he', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', 'he', 'Hello'], 'LiSi']
['ZhangSan', 'LiSi', 'WangWu', ['alex', '李四', 'Hello'], 'LiSi']

• 列表在循环打印

names = ["ZhangSan","LiSi","WangWu",["alex","he","Hello"],"LiSi"]
for i in names:#可以省略为for i in names[:]   或者 for i in names[::]
    print(i)


结果：
ZhangSan
LiSi
WangWu
['alex', 'he', 'Hello']
LiSi

•  元祖：

元祖是一个只读列表，只能查询，不能进行增、删、改

写法：names = ("Alex","ZhangSan","LiSi")

• 列表的切片

names = ["ZhangSan","LiSi","WangWu",["alex","he","Hello"],"LiSi"]
#类似 range(0,10,2)这样进行切片,从头到尾，间隔1个打印
for i in names[0:-1:2]:#可以省略为for i in names[::2]:
    print(i)


结果：
ZhangSan
WangWu