擅长:python、mysql、java
<p>我想这可以满足你的要求:</p>
<pre><code>2014-06-05 09:37:57 [tmp]$ export VAR1="a"
2014-06-05 09:38:01 [tmp]$ export VAR2="b"
2014-06-05 09:38:05 [tmp]$ export VAR3="c"
2014-06-05 09:38:08 [tmp]$ export VAR4="d"
2014-06-05 09:38:12 [tmp]$ python
Python 2.7.3 (default, Feb 27 2014, 19:58:35)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from os import environ
>>> environ['VAR1']
'a'
>>> environ['VAR2']
'b'
>>> environ['VAR3']
'c'
>>> environ['VAR4']
'd'
>>> environ['VAR5']
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/UserDict.py", line 23, in __getitem__
raise KeyError(key)
KeyError: 'VAR5'
</code></pre>
<p>记住捕获KeyError并相应地响应,或者使用get方法(从dict类)并指定在密钥不存在时使用的默认值:</p>
<pre><code>>>> environ.get('VAR5', 'not present')
'not present'
</code></pre>
<p>更多:
<a href="https://docs.python.org/2/library/os.html" rel="nofollow">https://docs.python.org/2/library/os.html</a></p>