标签：执行顺序 内容 zhang [1] print 等于 顺序 打印 使用
深copy 浅copy 循环 步长切片
name=["zhangyang","guyun","guyun","xiangpeng","xia"] name2=name.copy() name[3]="向鹏" print(name) print(name2) 从上到下是有执行顺序的 [‘zhangyang‘, ‘guyun‘, ‘guyun‘, ‘向鹏‘, ‘xia‘] [‘zhangyang‘, ‘guyun‘, ‘guyun‘, ‘xiangpeng‘, ‘xia‘]
name=["zhangyang","guyun","xiangpeng",["alex,jack"],"xia"] name2=name.copy() name[2]="向鹏" name[3][0]="ALEX" print(name) print(name2) 这个copy是浅copy [‘zhangyang‘, ‘guyun‘, ‘向鹏‘, [‘ALEX‘], ‘xia‘] [‘zhangyang‘, ‘guyun‘, ‘xiangpeng‘, [‘ALEX‘], ‘xia‘]
列表：
a=[1,2,3]
b=a
a[1]=555
b=[1,555,3] //注意这里b不在是等于[1,2,3]
a=[1,2,3] b=a a[1]=555 print(a) print(b) [1, 555, 3] [1, 555, 3]
深copy,这时候的输出结果是完全两份不同的数据，互补干扰
import copy name=["zhangyang","guyun","xiangpeng",["alex,jack"],"xia"] name2=copy.deepcopy(name) name[2]="向鹏" name[3][0]="ALEX" print(name) print(name2) 这个copy是浅copy [‘zhangyang‘, ‘guyun‘, ‘向鹏‘, [‘ALEX‘], ‘xia‘] [‘zhangyang‘, ‘guyun‘, ‘xiangpeng‘, [‘alex,jack‘], ‘xia‘]
报名字的循环
name=["zhangyang","guyun","xiangpeng",["alex,jack"],"xia"] for i in name: print(i) zhangyang guyun xiangpeng [‘alex,jack‘] xia
从第0个开始到第最后一个，跳一个显示一个 name=["zhangyang","guyun","xiangpeng",["alex,jack"],"xia"] print(name[0:-1:2]) [‘zhangyang‘, ‘xiangpeng‘]
0和-1可以省略掉 name=["zhangyang","guyun","xiangpeng","alex","xia"] print(name[::2]) [‘zhangyang‘, ‘xiangpeng‘, ‘xia‘]
从0到-1全部打印，因为0 和-1可以省略掉 name=["zhangyang","guyun","xiangpeng",["alex,jack"],"xia"] print(name[:]) [‘zhangyang‘, ‘guyun‘, ‘xiangpeng‘, [‘alex,jack‘], ‘xia‘]
copy是对原内容的引用
person=[‘name‘,[‘a‘,100]]
p1=copy.copy(person)
p2=person[:]
p3=list(person)
person=[‘name‘,[‘a‘,100]]
p1=person[:]
p2=person[:]
print(p1)
print(p2)
[‘name‘, [‘a‘, 100]]
[‘name‘, [‘a‘, 100]]
浅 copy:创建联合账号
person=[‘name‘,[‘saving‘,100]]
p1=person[:]
p2=person[:]
p1[0]="Alex"
p2[0]="fengjie"
print(p1)
print(p2)
[‘Alex‘, [‘saving‘, 100]]
[‘fengjie‘, [‘saving‘, 100]]
两个人的联合账号都有100元
person=[‘name‘,[‘saving‘,100]]
p1=person[:]
p2=person[:]
p1[0]="Alex"
p2[0]="fengjie"
p1[1][1]=30 //变成30元，这时用的是浅copy
print(p1)
print(p2)
[‘Alex‘, [‘saving‘, 30]]
[‘fengjie‘, [‘saving‘, 30]]
标签：执行顺序 内容 zhang [1] print 等于 顺序 打印 使用
原文地址：https://www.cnblogs.com/googlewang/p/10704663.html
