拷贝、文件操作 

 1 拷贝
 2 import copy
 3 L = [1,1,2,3,4,5,6,7,8,[1,2,3]]
 4 # L2 = L # 浅拷贝，内存地址不变
 5 # L2 = L.copy()  #浅拷贝，内存地址变化
 6 # L2 = copy.copy(L) #浅拷贝
 7 
 8 L2 = copy.deepcopy(L) #深拷贝
 9 L2[-1][1] = " 胡月梅"
10 
11 # L2 = [1,1,2,3,4,5,6,7,8]
12 print(L)
13 print(L2)
14 
15 # for i in L2:
16 #     if i % 2 != 0:  #取余数
17 #         L.remove(i)
18 # print(L)
19 # 正在循环的list，删里面的元素会导致下标错乱，取值有误
20 # a = 5
21 # print(a%2)
22 
23 
24 文件操作
25 # f = open("a.txt",'r',encoding="utf-8")
26 # # f.write("胡月梅")
27 # # result = f.read() #读取所有的内容，返回的字符串
28 # # result = f.readlines()# 读取所有的内容，返回的是list
29 # # result = f.readline() #读取一行
30 #
31 # print("f.readline()",f.readline())
32 # print("f.read",f.read())
33 # f.seek(0)  #文件指针移到开头
34 # print("f.readlines()",f.readlines())
35 # f.close()
36 nums = ["1","2","3","5"]
37 f = open("a.txt",'w',encoding="utf-8")
38 # for i in nums:
39 #     i = str(i) + '\n'
40 #     f.write(i) #只能写字符串   #如果是列表的话 用write 需要用循环
41 #
42 f.writelines(nums) #如果是列表的话 用writelines 不需要循环
43 f.close()

 

posted @ 2021-05-13 17:39  等待iing  阅读(104)  评论(0)    收藏  举报