gistfile1.py

In [11]: x
Out[11]: <pygments.lexers.RstLexer>

In [12]: x.name
Out[12]: 'reStructuredText'

In [13]: lexers.get_lexer_by_name(x.name)
---------------------------------------------------------------------------
ClassNotFound                             Traceback (most recent call last)
<ipython-input-13-1e0731e95ff2> in <module>()
----> 1 lexers.get_lexer_by_name(x.name)

/usr/lib/python2.7/site-packages/pygments/lexers/__init__.pyc in get_lexer_by_name(_alias, **options)
     78         if _alias in cls.aliases:
     79             return cls(**options)
---> 80     raise ClassNotFound('no lexer for alias %r found' % _alias)
     81 
     82 

ClassNotFound: no lexer for alias 'reStructuredText' found

Do you know how computers work?

They don't.