sys 模块

import sys

print(sys.argv)


#输出
$ python test.py helo world
>>>
['test.py', 'helo', 'world']  #把执行脚本时传递的参数获取到了

import sys

print(sys.path)
>>>
['/Users/xhxu/python/python3/test', '/Users/xhxu/python/python3', '/Users/xhxu/.pyenv/versions/3.5.3/lib/python35.zip', '/Users/xhxu/.pyenv/versions/3.5.3/lib/python3.5', '/Users/xhxu/.pyenv/versions/3.5.3/lib/python3.5/plat-darwin', '/Users/xhxu/.pyenv/versions/3.5.3/lib/python3.5/lib-dynload', '/Users/xhxu/.pyenv/versions/env3.5.3/lib/python3.5/site-packages', '/Users/xhxu/.pyenv/versions/env3.5.3/lib/python3.5/site-packages/setuptools-28.8.0-py3.5.egg', '/Users/xhxu/.pyenv/versions/env3.5.3/lib/python3.5/site-packages/pip-9.0.1-py3.5.egg']

sys.path.append(BASE_DIR)

退出程序，正常退出时exit(``0``)

In [1]: import sys

In [2]: a = []

In [3]: b = a

In [4]: sys.getrefcount(a)
Out[4]: 27

In [13]: sys.platform
Out[13]: 'darwin'

In [39]: sys.path
Out[39]:
['/Users/rxu/.pyenv/versions/3.5.3/envs/general_3.5.3/bin',
 '/Users/rxu/.pyenv/versions/3.5.3/lib/python35.zip',
 '/Users/rxu/.pyenv/versions/3.5.3/lib/python3.5',
 '/Users/rxu/.pyenv/versions/3.5.3/lib/python3.5/plat-darwin',
 '/Users/rxu/.pyenv/versions/3.5.3/lib/python3.5/lib-dynload',
 '',
 '/Users/rxu/.pyenv/versions/3.5.3/envs/general_3.5.3/lib/python3.5/site-packages',
 '/Users/rxu/.pyenv/versions/3.5.3/envs/general_3.5.3/lib/python3.5/site-packages/IPython/extensions',
 '/Users/rxu/.ipython']

sys.setrecursionlimit(1000000)

>>> def factorial(n):
...     return 1 if n<=1 else n*factorial(n-1)

>>> factorial(5000)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in factorial
  File "<stdin>", line 2, in factorial
  File "<stdin>", line 2, in factorial
  [Previous line repeated 995 more times]
RecursionError: maximum recursion depth exceeded in comparison

>>> sys.setrecursionlimit(1000000)
>>> factorial(5000)