Exercise in Basic Python data structures - Lists and Dicts

# HW Exercise in Basic Python data structures - Lists and Dicts
# Reproduce the following python interactive listing using different data of your choosing, e.g., choose different variable names and
# data strings other than ‘Bob Smith’ and ‘Sue Jones’

>>> bob = ['Bob Smith', 42, 30000, 'software']
>>> sue = ['Sue Jones', 45, 40000, 'hardware']

>>> bob[0], sue[2]             # fetch name, pay
('Bob Smith', 40000)

>>> bob[0].split()[-1]         # what's bob's last name?
'Smith'

>>> sue[2] *= 1.25             # give sue a 25% raise
>>> sue

['Sue Jones', 45, 50000.0, 'hardware']

>>> people = [bob, sue ]        # reference in list of lists

>>> for person in people:
        print(person)

['Bob Smith', 42, 30000, 'software']
['Sue Jones', 45, 50000.0, 'hardware']

>>> people[1][0]

'Sue Jones'

>>> for person in people:
        print(person[0].split()[-1])           # print last names
        person[2] *= 1.20                      # give each a 20% raise

Smith
Jones

>>> for person in people: print(person[2])     # check new pay

36000.0
60000.0

>>> pays = [person[2] for person in people]    # collect all pay
>>> pays

[36000.0, 60000.0]

>>> pays = map((lambda x: x[2]), people)   # ditto (map is a generator in 3.X)

>>> list(pays)

[36000.0, 60000.0]
>>> sum(person[2] for person in people)       # generator expression, sum built-in

96000.0

>>> people.append(['Tom', 50, 0, None])
>>> len(people)

3

>>> people[-1][0]

'Tom'

>>> NAME, AGE, PAY = range(3)                # 0, 1, and 2
>>> bob = ['Bob Smith', 42, 10000]
>>> bob[NAME]

'Bob Smith'

>>> PAY, bob[PAY]

(2, 10000)

>>> bob = [['name', 'Bob Smith'], ['age', 42], ['pay', 10000]]
>>> sue = [['name', 'Sue Jones'], ['age', 45], ['pay', 20000]]
>>> people = [bob, sue]

>>> for person in people:
        print(person[0][1], person[2][1])     # name, pay

Bob Smith 10000
Sue Jones 20000

>>> [person[0][1] for person in people]       # collect names

['Bob Smith', 'Sue Jones']

>>> for person in people:
        print(person[0][1].split()[-1])       # get last names
        person[2][1] *= 1.10                  # give a 10% raise

Smith
Jones

>>> for person in people: print(person[2])

['pay', 11000.0]
['pay', 22000.0]

>>> for person in people:
        for (name, value) in person:
            if name == 'name': print(value)   # find a specific field

Bob Smith
Sue Jones

>>> def field(record, label):
        for (fname, fvalue) in record:
            if fname == label:              # find any field by name
                return fvalue

>>> field(bob, 'name')
'Bob Smith'

>>> field(sue, 'pay')
22000.0

>>> for rec in people:
        print(field(rec, 'age'))              # print all ages

42
45

>>> bob = {'name': 'Bob Smith', 'age': 42, 'pay': 30000, 'job': 'dev'}
>>> sue = {'name': 'Sue Jones', 'age': 45, 'pay': 40000, 'job': 'hdw'}


>>> bob['name'], sue['pay']            # not bob[0], sue[2]

('Bob Smith', 40000)

>>> bob['name'].split()[-1]

'Smith'

>>> sue['pay'] *= 1.10
>>> sue['pay']

44000.0

>>> bob = dict(name='Bob Smith', age=42, pay=30000, job='dev')
>>> sue = dict(name='Sue Jones', age=45, pay=40000, job='hdw')


>>> bob

{'pay': 30000, 'job': 'dev', 'age': 42, 'name': 'Bob Smith'}

>>> sue

{'pay': 40000, 'job': 'hdw', 'age': 45, 'name': 'Sue Jones'}

>>> sue = {}
>>> sue['name'] = 'Sue Jones'
>>> sue['age']  = 45
>>> sue['pay']  = 40000
>>> sue['job']  = 'hdw'
>>> sue

{'job': 'hdw', 'pay': 40000, 'age': 45, 'name': 'Sue Jones'}


>>> names  = ['name', 'age', 'pay', 'job']
>>> values = ['Sue Jones', 45, 40000, 'hdw']
>>> list(zip(names, values))

[('name', 'Sue Jones'), ('age', 45), ('pay', 40000), ('job', 'hdw')]

>>> sue = dict(zip(names, values))
>>> sue

{'job': 'hdw', 'pay': 40000, 'age': 45, 'name': 'Sue Jones'}

>>> fields = ('name', 'age', 'job', 'pay')
>>> record = dict.fromkeys(fields, '?')
>>> record

{'job': '?', 'pay': '?', 'age': '?', 'name': '?'}

>>> bob

{'pay': 30000, 'job': 'dev', 'age': 42, 'name': 'Bob Smith'}

>>> sue

{'job': 'hdw', 'pay': 40000, 'age': 45, 'name': 'Sue Jones'}

>>> people = [bob, sue]             # reference in a list
>>> for person in people:
        print(person['name'], person['pay'], sep=', ')    # all pay

Bob Smith, 30000
Sue Jones, 40000

>>> for person in people:
        if person['name'] == 'Sue Jones':   # fetch sue's pay
            print(person['pay'])

40000

>>> names = [person['name'] for person in people]         # collect names
>>> names

['Bob Smith', 'Sue Jones']

>>> list(map((lambda x: x['name']), people))              # ditto, generate

['Bob Smith', 'Sue Jones']

>>> sum(person['pay'] for person in people)               # sum all pay

70000

>>> for person in people:
        print(person['name'].split()[-1])                 # last name
        person['pay'] *= 1.10                             # a 10% raise

Smith
Jones

>>> for person in people: print(person['pay'])

33000.0
44000.0

>>> bob2 = {'name': {'first': 'Bob', 'last': 'Smith'},
            'age':  42,
            'job':  ['software', 'writing'],
            'pay':  (40000, 50000)}

>>> bob2['name']                            # bob's full name

{'last': 'Smith', 'first': 'Bob'}

>>> bob2['name']['last']                    # bob's last name\

'Smith'

>>> bob2['pay'][1]                          # bob's upper pay

50000

>>> for job in bob2['job']: print(job)      # all of bob's jobs

software
writing

>> bob2['job'][-1]                          # bob's last job

'writing'

>>> bob2['job'].append('janitor')           # bob gets a new job

>>> bob2

{'job': ['software', 'writing', 'janitor'], 'pay': (40000, 50000), 'age': 42, 'name':

{'last': 'Smith', 'first': 'Bob'}}

>>> bob = dict(name='Bob Smith', age=42, pay=30000, job='dev')
>>> sue = dict(name='Sue Jones', age=45, pay=40000, job='hdw')
>>> bob

{'pay': 30000, 'job': 'dev', 'age': 42, 'name': 'Bob Smith'}

>>> db = {}
>>> db['bob'] = bob                      # reference in a dict of dicts
>>> db['sue'] = sue
>>> db['bob']['name']                    # fetch bob's name

'Bob Smith'

>>> db['sue']['pay'] = 50000             # change sue's pay
>>> db['sue']['pay']                     # fetch sue's pay

50000

>>> db

{'bob': {'pay': 30000, 'job': 'dev', 'age': 42, 'name': 'Bob Smith'}, 'sue': {'pay': 50000, 'job': 'hdw', 'age': 45, 'name': 'Sue Jones'}}

>>> import pprint
>>> pprint.pprint(db)

{'bob': {'age': 42, 'job': 'dev', 'name': 'Bob Smith', 'pay': 30000},
 'sue': {'age': 45, 'job': 'hdw', 'name': 'Sue Jones', 'pay': 50000}}


>>> for key in db:
        print(key, '=>', db[key]['name'])

bob => Bob Smith
sue => Sue Jones

>>> for key in db:
        print(key, '=>', db[key]['pay'])

bob => 30000
sue => 50000

>>> for key in db:
        print(db[key]['name'].split()[-1])
        db[key]['pay'] *= 1.10

Smith
Jones

>>> for record in db.values(): print(record['pay'])

33000.0
55000.0

>>> x = [db[key]['name'] for key in db]
>>> x

['Bob Smith', 'Sue Jones']

>>> x = [rec['name'] for rec in db.values()]
>>> x

['Bob Smith', 'Sue Jones']

>>> db['tom'] = dict(name='Tom', age=50, job=None, pay=0)
>>> db['tom']

{'pay': 0, 'job': None, 'age': 50, 'name': 'To'}

>>> db['tom']['name']

'Tom'

>>> list(db.keys())

['bob', 'sue', 'tom']

>>> len(db)

3

>>> [rec['age'] for rec in db.values()]

[42, 45, 50]