官方文档有句话"allows you to call any program"，并且：
helps you write shell scripts in Python by giving you the good features of Bash
第一句话助你在Python中轻松调用自己的程序，第二句则给你机会和Shell这种土豪交朋友
㈠ 调用系统的程序
[python]
>>> import sh
>>> print(sh.ls(‘/home/mysql‘))
cdio_bak.sql mysql-5.5.16.tar.gz
mm percona-xtrabackup-2.1.4-656-Linux-i686.tar.gz
mysql percona-xtrabackup-2.1.4-Linux-i686
mysql-5.5.16 startmysql.sh
㈡ 调用自己的程序
[python]
>>> import sh
>>> r=sh.Command(‘/root/dd.py‘)
>>> r()
hello,DBA
㈢ bake命令参数
[python]
>>> import sh
>>> du=sh.du.bake(‘-shc‘)
>>> print (du(‘/home/mysql‘))
1.1G /home/mysql
1.1G 总计
㈣ glob列出文件
[python]
>>> import sh
>>> list=sh.glob(‘/root/mm/*‘)
>>> print list
[‘/root/mm/Backup‘, ‘/root/mm/Usplash‘, ‘/root/mm/AWN‘, ‘/root/mm/Wallpapers‘, ‘/root/mm/GRUB‘, ‘/root/mm/Mozilla‘]
㈤ 管道
[python]
>>> print(sh.sort(sh.du(sh.glob(‘*‘),‘-shc‘),‘-rn‘))
712K distribute-0.6.49.tar.gz
672K setuptools-1.1.5.tar.gz
548K get-pip.py
管道是有序的，默认由内而外，但如果需要并行呢？加个_piped=True
[python]
>>> for line in sh.tr(sh.tail("-f", "/home/mysql/mysql/log/alert.log", _piped=True), "[:upper:]", "[:lower:]", _iter=True):
... print line
...
innodb: doublewrite buffer not found: creating new
innodb: doublewrite buffer created
innodb: 127 rollback segment(s) active.
innodb: creating foreign key constraint system tables
innodb: foreign key constraint system tables created