def flatten_dictionary(dictionary):
  return flat(dictionary)

def flat(dictionary):
  if len(dictionary) == 0:
    return {}
  results = {}
  for key, value in iter(dictionary.items()):
    if type(value) is dict:
      sub_dict = flat(value)
      for k, v in iter(sub_dict.items()):
        if len(key) == 0:
          results[k] = v
        elif len(k) == 0:
          results[key] = v
        else:
          results[key + "." + k] = v
    else:
      results[key] = value
  return results

# each key i check if the value is string or integer
# each nested value
dictionary = {
            "Key1" : "1",
            "Key2" : {
                "a" : "2",
                "b" : "3",
                "c" : {
                    "d" : "3",
                    "e" : "1"
                }
            }
        }

print(flatten_dictionary(dictionary))