<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def index_from_id(self,Id):
 """Return the row of given Id if it'exists, otherwise None. Only works with pseudo-acces"""

        try:
            return [a.Id for a in self].index(Id)
        except IndexError:
            return