Assigning values from dictionary to object

Question

I very often need to do something like this:

"Some dictionary with values obtained somehow (e.g. submitted form values)"
my_dict = {
    'name': 'John',
    'surname': 'Doe',
    'age': 27,
    'hair_color': 'green',
}

"object person is some instance of class representing person"
person.name = my_dict['name']
person.surname = my_dict['surname']
person.age = my_dict['age']
person.hair_color = my_dict['hair_color']

I think this is a lot of repetition. What approach do you use?

score 8 · Accepted Answer · answered Sep 24 '12 at 16:23

8

for attr, val in my_dict.items():
    setattr(person, attr, val)

If my_dict might contain any keys that you don't want to copy to person, create a list of keys you do want to copy and do something like this:

key_list = ['name', 'surname', 'age', 'hair_color']
for attr in key_list:
    setattr(person, attr, my_dict[attr])

answered Sep 24 '12 at 16:23

Andrew Clark

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note: make sure you filter/santizie my_dict (restrict the keys), otherwise the user can update arbitrary attributes. – Karoly Horvath Sep 24 '12 at 16:25
to restrict the keys you could use an explicit whitelist such as `key_list` even if `my_dict` has no unused keys. – jfs Sep 24 '12 at 16:33

score 1 · Answer 2 · answered Sep 24 '12 at 16:24

1

As an instance's attributes can be accessed via a dictionary, so use instance.__dict__:

>>> for item in my_dict:
        person.__dict__[item]=my_dict[item]

answered Sep 24 '12 at 16:24

Ashwini Chaudhary

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This bypasses setter properties and `__setattr__`. – ecatmur Sep 24 '12 at 16:26

score 0 · Answer 3 · edited May 23 '17 at 12:23

0

There is a pretty good Q/A for this already: How to create objects on the fly in python?

In your case:

person = type('Person', (object,), my_dict)
print person.name

edited May 23 '17 at 12:23

Community

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answered Sep 24 '12 at 16:29

Benedict

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Assigning values from dictionary to object

3 Answers3