code: def get_keys(data_list, leading_columns=LEADING_COLUMNS):
      
      all_keys = set().union(*(list(d.keys()) for d in data_list))
  
      leading_keys = []
  
      for key in leading_columns:
          if key not in all_keys:
              continue
          leading_keys.append(key)
          all_keys.remove(key)
  
      return leading_keys + sorted(all_keys)
docs: Gets all possible keys from a list of dicts, sorting by leading_columns first
  
      Args:
          data_list: list of dicts to pull keys from
          leading_columns: list of keys to put first in the result
  
      Returns:
          list of keys to be included as columns in excel worksheet