<human>:  What is a good Python function to flatten a nested dictionary.
<bot>: Here is a Python function to flatten a nested dictionary

import random

def flatten(dictionary):
  """
  Flatten a nested dictionaary.
  """
  return {key: value for key, value in list(dictionary.items()) if not isinstance(value, dict)}

# Enter the dictionary
dictionary = {'a': {'b': {'c': 'd'}}}

# Calling the function
print((flatten(dictionary)))

#Example Output
# {}

#Remember to inspect code for bugs.