5.7 Missing Values

If NameMapper can not find a Python value for a Cheetah variable name, it will raise the NameMapper.NotFound exception. You can use the #errorCatcher directive (section 10.2) or errorCatcher Template constructor argument (section 4.1) to specify an alternate behaviour. BUT BE AWARE THAT errorCatcher IS ONLY INTENDED FOR DEBUGGING!

To provide a default value for a placeholder, write it like this: $getVar('varName', 'default value'). If you don't specify a default and the variable is missing, NameMapper.NotFound will be raised.