def merge_dict(*args):
  """ Merges any number of dictionaries into a single dictionary.

    # Notes

    In Python 3.5+, you can just do this:
    ```python
    r = {**x, **y}
    ```
    But if you want a single expression in Python 3.4 and below:
    ```python
    r = merge_dict(x, y)
    ```
  """
  result = {}
  for x in args:
    result.update(x)
  return result