code: def uncurry_nested_dictionary(curried_dict):
      """
      Transform dictionary from (key_a -> key_b -> float) to
      (key_a, key_b) -> float
      """
      result = {}
      for a, a_dict in curried_dict.items():
          for b, value in a_dict.items():
              result[(a, b)] = value
      return result
  
imports: from collections import defaultdict
  import numpy
  from scipy.sparse import dok_matrix
label_desc: Use image node_id 11 for calling a global function with example usage: uncurry_nested_dictionary(curried_dict) and returns: result