Building a dynamic dictionary mapper inside function

Question

I have one function attrmapper. The purpose for this function is to build a dictionary, information, as attribution for the object. Is there a better way for me to rewrite the obj.information.update( part? The part to update information attribution will be more clear? Because if we replace mapping to a long string, the function will be really hard to read.

mapping = {
'firstname': 'this is fisrt name: {} should be string',
'lastname': 'this is last name: {} should be string',
'address': 'this is address {} should be address1, address2, state, state and zipcode',
'phone_number': 'this is phone number {} should be 0 to 9',
'gender': 'this is gender {}: should be male or female',
'company': 'this is company {} should be start with G',
'position': 'this is position {} should be engineer, manager and level',
'aAbreu': 'Albert Abreu',
'cGreen': 'Chad Green',
'lCessa': 'Luis Cessa',
'aJudge': 'Aaron Judge',
'jEllsbury': 'Jacoby Ellsbury',
    }
def attrmapper(obj: object) -> object:
    information = {}
    for name in ['aAbreu', 'cGreen', 'lCessa', 'aJudge', 'jEllsbury']:
        obj.information.update(
            {'{}_firstname'.format(name): mapping.get('firstname').format(mapping.get(name)),
            '{}_lastname'.format(name): mapping.get('lastname').format(mapping.get(name)),
            '{}_address'.format(name): mapping.get('address').format(mapping.get(name)),
            '{}_phone_number'.format(name): mapping.get('phone_number').format(mapping.get(name)),
            '{}_company'.format(name): mapping.get('company').format(mapping.get(name)),
            '{}_position'.format(name): mapping.get('firstname').format(mapping.get(name))})
    return obj

Answer 1

We can do a dictionary comprehension and avoid code repetition:

NAMES = ['aAbreu', 'cGreen', 'lCessa', 'aJudge', 'jEllsbury']
ATTRIBUTES = ['firstname', 'lastname', 'address', 'phone_number', 'company', 'position']
for name in NAMES:
    full_name = mapping.get(name)
    obj.information.update({
        f'{name}_{attr}': mapping.get(attr).format(full_name)
        for attr in ATTRIBUTES
    })

Note the use of an f-string for the key definition.

And, aside from that, I think you can remove the information variable as it is unused.

And, both my and your versions of the code don't handle missing keys situation - what if there is no such key in mapping?