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

>>> 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

>>> import sh

>>> r=sh.Command('/root/dd.py')

>>> r()

hello,DBA

㈢ bake命令参数

>>> 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

>>> 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

>>> 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

>>> 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

By DBA_WaterBin

2013-09-30

Good Luck