<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_value(self, item, default=None):
 """Get the value of a child"""

        try:
            return self[item].value
        except (AttributeError, KeyError) as e:
            return default