abstract syntax tree - How to store AST Children information(python) -

i relatively new python , pycparser. have parsed c file ast using c-to-c.py file https://github.com/eliben/pycparser. trying make cfg using ast unable store information in .show() string. how go storing .show() information, have tried use test=ast.children()[0][1].show() when try print test out states "none". there way of storing it? or there method can use read through .show() information. thank you.

def show(self, buf=sys.stdout, offset=0, attrnames=false, nodenames=false, showcoord=false, _my_node_name=none):         """ pretty print node , attributes ,             children (recursively) buffer.              buf:                 open io buffer node printed.              offset:                 initial offset (amount of leading spaces)              attrnames:                 true if want see attribute names in                 name=value pairs. false see values.              nodenames:                 true if want see actual node names                 within parents.              showcoord:                 want coordinates of each node                 displayed.         """         lead = ' ' * offset         if nodenames , _my_node_name not none:             buf.write(lead + self.__class__.__name__+ ' <' + _my_node_name + '>: ')         else:             buf.write(lead + self.__class__.__name__+ ': ')          if self.attr_names:             if attrnames:                 nvlist = [(n, getattr(self,n)) n in self.attr_names]                 attrstr = ', '.join('%s=%s' % nv nv in nvlist)             else:                 vlist = [getattr(self, n) n in self.attr_names]                 attrstr = ', '.join('%s' % v v in vlist)             buf.write(attrstr)          if showcoord:             buf.write(' (at %s)' % self.coord)         buf.write('\n')          (child_name, child) in self.children():             child.show(                 buf,                 offset=offset + 2,                 attrnames=attrnames,                 nodenames=nodenames,                 showcoord=showcoord,                 _my_node_name=child_name) 

as can see documentation string, show takes buf parameter print representation. default it's sys.stdout can pass own.

for full flexibility can use stringio - let grab output string.