python学习记录2

 1 #!/usr/bin/env python
 2 # _*_ coding: UTF-8 _*_
 3 # Author:taoke
 4 import sys
 5 print(sys.path)#打印环境变量
 6 print(sys.argv[0])#当前文件相对路径,sys.argv是一个列表，第一个元素为程序本身的相对路径，之后的为程序运行是的输入参数
 7 
 8 import os
 9 #cmd_res= os.system("dir")#执行命令不保存结果
10 cmd_res = os.popen("dir").read()#保存命令执行的结果并返回保存地址
11 print("-->",cmd_res)
12 os.mkdir("new_dir")#创建一个目录

1 #!/usr/bin/env python
2 # _*_ coding: UTF-8 _*_
3 # Author:taoke
4 str = "我爱北京天安门"
5 str_endode = str.encode("utf-8")
6 str_endode_decode = str_endode.decode("utf-8")
7 print(str,type(str))
8 print(str_endode,type(str_endode))
9 print(str_endode_decode,type(str_endode_decode))

运行结果：
我爱北京天安门 <class ‘str‘>
b‘\xe6\x88\x91\xe7\x88\xb1\xe5\x8c\x97\xe4\xba\xac\xe5\xa4\xa9\xe5\xae\x89\xe9\x97\xa8‘ <class ‘bytes‘>
我爱北京天安门 <class ‘str‘>

 1 #!/usr/bin/env python
 2 # _*_ coding: UTF-8 _*_
 3 # Author:taoke
 4 names = ["xiaoming","xiaohong","xiaohei","xiaoxiao"]
 5 
 6 print(names)
 7 print(names[0],names[2])
 8 print(names[1:3])#顾头不顾尾，切片
 9 
10 names.append("xiaobingbing")
11 print(names)
12 names.insert(1,"renma")
13 print(names)

#!/usr/bin/env python
# _*_ coding: UTF-8 _*_
# Author:taoke
import copy
names = ["xiaoming","xiaohong",["Jack","Toms"],"xiaohei","xiaoxiao"]
names2 = names.copy()#浅copy
names3 = copy.copy(names)#浅copy
names4 = copy.deepcopy(names)#深copy
names[2][0] = "JACK"
print(names)
print(names2)
print(names3)
print(names4)

运行结果：
[‘xiaoming‘, ‘xiaohong‘, [‘JACK‘, ‘Toms‘], ‘xiaohei‘, ‘xiaoxiao‘]
[‘xiaoming‘, ‘xiaohong‘, [‘JACK‘, ‘Toms‘], ‘xiaohei‘, ‘xiaoxiao‘]
[‘xiaoming‘, ‘xiaohong‘, [‘JACK‘, ‘Toms‘], ‘xiaohei‘, ‘xiaoxiao‘]
[‘xiaoming‘, ‘xiaohong‘, [‘Jack‘, ‘Toms‘], ‘xiaohei‘, ‘xiaoxiao‘]