please fill in addData and show Data

more_shelve.py

import shelve
def addData(data):
    #figure how to add data
    pass

def showData(data):
    # display your organized data
    pass
init_data = shelve.open('sample.db')

## Check the init_ata is well organized, or you need to organized by yourself

print "commands ? press A to add a name, press L to list all names"
print ">",

command = raw_input()
if command == 'A':
    print "data to add is: "
    addData(init_data)
elif command == 'L':

    showData(init_data)
    print "-- end of data --"

else:
    print 'you should press A or L'