Here is an example of how you can create a dictionary that contains keys and values.

#!/usr/bin/python
dictionary = {
  "foo": "Hello",
  "bar": "World"
}
print(dictionary)

Which should print the following.

{'foo': 'Hello', 'bar': 'World'}

Here is how you can remove the foo key (and it's value) using pop.

#!/usr/bin/python3
dictionary = {
  "foo": "Hello",
  "bar": "World"
}

dictionary.pop('foo')

print(dictionary)

Which should now print the following.

{'bar': 'World'}

And here is how you could remove a key and every key and value at and below the key.

#!/usr/bin/python3
dictionary = {
  'domains': {
    'foo.example.com': {
      'alias': 'foo',
      'region': 'us-east-1'},
    'bar.example.com': {
      'alias': 'bar',
      'region': 'us-east-1'}
    }
}

dictionary['domains'].pop('foo.example.com')

print(dictionary)