1. You can try a specific rule by writing this:
   
tree = parser.parse(content,:root => "rule_name")

2. I usually have my code structured like this, to get some info about where the parser chokes:

   
   if tree
       puts "succesful"
   else
       puts "unsuccesful at #{parser.index}"
       puts parser.failure_reason
   end
   

Hope this helps you as much as it helped me.

print "Something %s" % value

The fix is to change it to:

print "Something %s" % str(value)

Just a simple usage example:

using System.Xml;
...
XmlDocument doc = new XmlDocument();
// loading a file
doc.Load("file.xml");

// searching for multiple nodes via XPath; this will select all  elements wherever they may be
XmlNodeList books = doc.SelectNodes("//books");

foreach(XmlNode node in books)
{
   // getting attributes; assuming <book Author="Whatever">
   XmlAttribute author = node.Attributes["Author"];
   string value = author.Value;
}

python manage.py dumpdata auth > initial_data.json
python manage.py syncdb

Make sure to modify the initial.json file, if you want to change the name/mail of the superuser.

class MyModelForm(ModelForm):
   class Meta:
      model = MyModel
      fields= ("path")

It led to a strange error, saying django.core.exceptions.FieldError: Unknown field(s) (a, p, t, h). Of course, the fix was to specify the fields like:

class MyModelForm(ModelForm):
   class Meta:
      model = MyModel
      fields= ("path",)

no such file to load — ffi_c

The fix was to install version 1.0.9 of the ffi gem:

gem uninstall ffi
gem install ffi -v 1.0.9