Sort a list of dictionaries by the only dictionary key

[Calab]

I have the following structure:

my_list = [{"Dog": {"sound":"bark"}}, {"Cow": {"sound":"moo"}}, {"Cat": {"sound":"meow"}}]

I want to get the following from this structure sorted or unsorted:

["Cat", "Cow", "Dog"]
# or
["Dog", "Cow", "Cat"]

The following ALMOST gives me what I want, but I'm getting a list of the complete dictionary instead of just the keys:

sorted(my_list, key=lambda x: x.keys[0])
[{'Cat': {'sound': 'meow'}}, {'Cow': {'sound': 'moo'}}, {'Dog': {'sound': 'bark'}}]

Using Python 2.7, how can I get the list of the first (only) key from each item in my list of dictionaries?

[buran]

my_list = [{'Cat': {'sound': 'meow'}}, {'Cow': {'sound': 'moo'}}, {'Dog': {'sound': 'bark'}}]
print [d.keys()[0] for d in my_list]

Output:
['Cat', 'Cow', 'Dog']

from itertools import chain
my_list = [{'Cat': {'sound': 'meow'}}, {'Cow': {'sound': 'moo'}}, {'Dog': {'sound': 'bark'}}]
print list(chain(*my_list))

Output:
['Cat', 'Cow', 'Dog']

Both snippets are python2