How to manipulate nested dictionaries with dotty

Table of Contents

Motivation

Sometimes a task which should be easy can be hard to accomplish in practice.

Manipulating nested dictionaries in Python seems to be such a task.

Accessing nested dictionaries looks like this

data = {
    'a': {
        'b': {
            'c': 'd'
        }
    }
}
assert data['a']['b']['c'] == 'd'

You have to chain the keys to get down to the nested dict and get the value for that key

You can install dotty with

pip install dotty-dict

from dotty_dict import dotty 
data = {
    'a': {
        'b': {
            'c': 'd'
        }
    }
}

dot = dotty(data)

assert 'a.b' in dot
assert dot['a.b.c'] == 'd'

After importing dotty you can wrap your existing vanilla Python dictionary in a dotty object.

Now you can access your nested values by chaining the key with the dot to a “key path”

data = {
    'a': {
        'b': {
            'c': 'd'
        }
    }
}
dot = dotty(data)
dot['a.b.c'] = 'e'
assert dot['a.b.c'] == {'c': 'e'}