Kayla Leonard DeHolton

This chunk of code does not work if one `variable_name` is a subset of another `variable_name`: [https://github.com/icecube/pisa/blob/master/pisa/core/events_pi.py#L553-L556](https://github.com/icecube/pisa/blob/master/pisa/core/events_pi.py#L553-L556) ``` for variable_name in variables: crit_str = crit_str.replace( variable_name, 'self["%s"]["%s"]' % (key, variable_name)...