Human: Give me a Python function to return dict keys lowercase. Assistant: 
Here is a Python function to return dict keys lowercase

import collections

def keys_lowercase(d):
    """Returns a copy of the keys of a dict with all keys lowercased."""
    return [k.lower() for k in list(d.keys())]

# Enter the dict
d = {"a": 1, "b": 2, "c": 3}

# Calling the function
print((keys_lowercase(d)))

#Example Output
# ['a', 'b', 'c']

#Remember to inspect code for bugs.