python字符串格式化、os模块和sys模块

1. python字符串格式化两种方式：(深入研究，东西还很多)

>>> 'Hello, %s' % 'world'
'Hello, world'
>>> 'Hi, %s, you have $%d.' % ('Michael', 1000000)
'Hi, Michael, you have $1000000.'

In [1]: '{0},{1}'.format('kzc',18) 
Out[1]: 'kzc,18'
In [2]: '{},{}'.format('kzc',18) 
Out[2]: 'kzc,18'
In [3]: '{1},{0},{1}'.format('kzc',18) 
Out[3]: '18,kzc,18'

2. urllib.request.urlretrieve()用法

urllib.request.urlretrieve(url, filename=None, reporthook=None, data=None)

3. os模块和sys模块

os.path.join("D:\","test.txt") #只是连接作用，不写不会主动创建
os.mkdir(os.path.join("D:\","test.txt"))
os.system("mkdir Test.txt") #在程序中引用命令行命令
os.getcmd()#获取当前路径