Create the union of a generic list of dictionaries.

dictionaries_union.py

def flatten_list(lst : list) -> list:
  """
  Description
  -----------
  Flatten an irregular list of lists (meaning that it can contain also non lists). If there are multiple nested lists
  the function must be used as many times as the nested order.
  """
  
  result = []

  if isinstance(lst, list):
   
    for i in lst:
      
      if isinstance(i, list):
        for j in i:
          result.append(j)
      else:
        result.append(i)
  else:
    result.append(lst)

  return result


def union_dictionary(ds : list) -> dict:
  """
  Description
  -----------
  Create the union of a list of dictionaries.
  """
  
  merged = dict()

  for d in ds:

    try:

        for key in d.keys():

          if key not in merged.keys():
            merged[key] = []

          merged[key].append(flatten_list(d[key]))
          merged[key] = flatten_list(merged[key])

    except:

      print('VALUE ERROR: Zero size dictionary given.')
      
  return merged