Getting the name which is not defined from NameError in python

dynamic-data, exception, expression, nameerror, python

Solution

>>> import re
>>> try:
...     a>0
... except (NameError,),e:
...     print re.findall("name '(\w+)' is not defined",str(e))[0]
a

If you don't want to use regex, you could do something like this instead

>>> str(e).split("'")[1]
'a'

Problem

As you know, if we simply do: ``` >>> a > 0 Traceback (most recent call last): File "<pyshell#1>", line 1, in <module> a > 0 NameError: name 'a' is not defined ``` Is there a way of catching the exception/error and extracting from it the value 'a'. I need this because I'm `eval`uating some dynamically created expressions, and would like to retrieve the names which are not defined in them. Hope I made myself clear. Thanks! Manuel

Original source