multiple keys in nested dictionary

Question

Code:

from operator import itemgetter
names = {
    'Bucky': 'Roberts',
    'Tom': 'Roberts',
    'Bernie' : 'Zunks',
    'Jenna' : 'Hayes',
    'Sally': 'Jones',
    'Amanda':'Roberts',
    'Tom':'Williams',
    'Dean':'Hayes',
    'Bernie':'Barbie',
    'Tom':'Jones'
    }
users = []
for k,v in names.items():
    users.append({'fname':k,'lname':v})
print(users)
for x in sorted(users, key=itemgetter('fname')):
    print(x)

Problem: For the last for loop (sorting one) to show all entries of dictionary names, I need all the entries i.e. duplicate keys (one-to-many mapping) also. But 2 Tom(s) and 1 Bernie are missed out while creating nested dictionary users. How can it be avoided using python 3.4?

Answer 1

A few possible improvements, but to your main issue, use the full name and a set as your structure, and split on space to create the other dict (which I am not sure you need):

names = {
    'Bucky Roberts',
    'Tom Roberts',
    'Bernie Zunks',
    'Jenna Hayes',
    'Sally Jones',
    'Amanda Roberts',
    'Tom Williams',
    'Dean Hayes',
    'Bernie Barbie',
    'Tom Jones'
}

users = []
for name in names:
    k, v = name.split()
    users.append({'fname':k,'lname':v})
for x in sorted(users, key=itemgetter('fname')):
    print(x)

Produces:

{'fname': 'Amanda', 'lname': 'Roberts'}
{'fname': 'Bernie', 'lname': 'Barbie'}
{'fname': 'Bernie', 'lname': 'Zunks'}
{'fname': 'Bucky', 'lname': 'Roberts'}
{'fname': 'Dean', 'lname': 'Hayes'}
{'fname': 'Jenna', 'lname': 'Hayes'}
{'fname': 'Sally', 'lname': 'Jones'}
{'fname': 'Tom', 'lname': 'Williams'}
{'fname': 'Tom', 'lname': 'Jones'}
{'fname': 'Tom', 'lname': 'Roberts'}

EDIT: using tuples and adding Betty Sue Johnson:

names = {
    ('Bucky', 'Roberts'),
    ('Betty Sue', 'Johnson'),
    ('Tom', 'Roberts'),
    ('Bernie', 'Zunks'),
    ('Jenna', 'Hayes'),
    ('Sally', 'Jones'),
    ('Amanda', 'Roberts'),
    ('Tom', 'Williams'),
    ('Dean', 'Hayes'),
    ('Bernie', 'Barbie'),
    ('Tom', 'Jones')
}

for each in sorted([{'fname':n[0], 'lname':n[1]} for n in names], key=itemgetter('fname')):
    print(each)

With output:

{'fname': 'Amanda', 'lname': 'Roberts'}
{'fname': 'Bernie', 'lname': 'Zunks'}
{'fname': 'Bernie', 'lname': 'Barbie'}
{'fname': 'Betty Sue', 'lname': 'Johnson'}
{'fname': 'Bucky', 'lname': 'Roberts'}
{'fname': 'Dean', 'lname': 'Hayes'}
{'fname': 'Jenna', 'lname': 'Hayes'}
{'fname': 'Sally', 'lname': 'Jones'}
{'fname': 'Tom', 'lname': 'Roberts'}
{'fname': 'Tom', 'lname': 'Williams'}
{'fname': 'Tom', 'lname': 'Jones'}

Answer 2

A dict cannot have duplicate keys, you might want to consider another data structure such as a list of tuples.

from operator import itemgetter

names = [
    ('Bucky', 'Roberts'),
    ('Tom', 'Roberts'),
    ('Bernie', 'Zunks'),
    ('Jenna', 'Hayes'),
    ('Sally', 'Jones'),
    ('Amanda','Roberts'),
    ('Tom', 'Williams'),
    ('Dean', 'Hayes'),
    ('Bernie', 'Barbie'),
    ('Tom', 'Jones')
    ]

users = [{'fname': k,'lname': v} for k, v in names]