1.编写tab.py的代码：
1 #!/usr/bin/env python
2 # python startup file
3 import sys
4 import readline
5 import rlcompleter
6 import atexit
7 import os
8 # tab completion
9 readline.parse_and_bind('tab: complete')
10 # history file
11 histfile = os.path.join(os.environ['HOME'], '.pythonhistory')
12 try:
13 readline.read_history_file(histfile)
14 except IOError:
15 pass
16 atexit.register(readline.write_history_file, histfile)
17 del os, histfile, readline, rlcompleter
2.把上面的代码，保存成tab.py文件，然后保存到下面的指定路径之一：
>>> import sys
>>> sys.path
['', '/home/hhl/dev/catkin_ws/devel/lib/python2.7/dist-packages', '/home/hhl/catkin_ws/devel/lib/python2.7/dist-packages', '/opt/ros/kinetic/lib/python2.7/dist-packages', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gtk-2.0']
3.使用：导入tab模块，可以使用tab键补全功能，例如：
>>> import tab
>>> import sys
>>> sys.
sys.__class__( sys.exit(
sys.__delattr__( sys.exitfunc(
sys.__dict__ sys.flags
sys.__displayhook__( sys.float_info
sys.__doc__ sys.float_repr_style
sys.__excepthook__( sys.getcheckinterval(
sys.__format__( sys.getdefaultencoding(
sys.__getattribute__( sys.getdlopenflags(
sys.__hash__( sys.getfilesystemencoding(
sys.__init__( sys.getprofile(
sys.__name__ sys.getrecursionlimit(
sys.__new__( sys.getrefcount(
sys.__package__ sys.getsizeof(
sys.__reduce__( sys.gettrace(
sys.__reduce_ex__( sys.hexversion
sys.__repr__( sys.long_info
sys.__setattr__( sys.maxint
sys.__sizeof__( sys.maxsize
sys.__stderr__ sys.maxunicode
sys.__stdin__ sys.meta_path
sys.__stdout__ sys.modules
sys.__str__( sys.path
sys.__subclasshook__( sys.path_hooks
sys._clear_type_cache( sys.path_importer_cache
sys._current_frames( sys.platform
sys._getframe( sys.prefix
sys._mercurial sys.ps1
sys._multiarch sys.ps2
sys.api_version sys.py3kwarning
sys.argv sys.pydebug
sys.builtin_module_names sys.setcheckinterval(
sys.byteorder sys.setdlopenflags(
sys.call_tracing( sys.setprofile(
sys.callstats( sys.setrecursionlimit(
sys.copyright sys.settrace(
sys.displayhook( sys.stderr
sys.dont_write_bytecode sys.stdin
sys.exc_clear( sys.stdout
sys.exc_info( sys.subversion
sys.exc_type sys.version
sys.excepthook( sys.version_info
sys.exec_prefix sys.warnoptions
sys.executable
>>> sys.