How can I modify nested dictionaries in Python?

How can I modify nested dictionaries in Python?

You can modify nested dictionaries by accessing the keys directly. For example, if you have a dictionary like data = {'a': {'b': 1}}, you can change the value of 'b' using data['a']['b'] = 2.

What if I want to add a new key to the nested dictionary?

You can add a new key by simply assigning a value to it. For instance, data['a']['c'] = 3 will add a new key 'c' with the value 3.

Can I remove a key from the nested dictionary?

Yes, you can remove a key using the del statement. For example, del data['a']['b'] will remove the key 'b' from the nested dictionary.

Is there a way to loop through all keys in a nested dictionary?

Yes, you can use a nested loop. For example:

for key, value in data.items():
    for sub_key, sub_value in value.items():
        print(sub_key, sub_value)