| from six import iteritems |
| |
| def merge_dictionaries(first, second): |
| """Given two dictionaries, create a third that defines all specified |
| key/value pairs. This merge_dictionaries is performed "deeply" on any nested |
| dictionaries. If a value is defined for the same key by both dictionaries, |
| an exception will be raised.""" |
| result = dict(first) |
| |
| for key, value in iteritems(second): |
| if key in result and result[key] != value: |
| if isinstance(result[key], dict) and isinstance(value, dict): |
| result[key] = merge_dictionaries(result[key], value) |
| elif result[key] != value: |
| raise TypeError("merge_dictionaries: refusing to overwrite " + |
| "attribute: `%s`" % key) |
| else: |
| result[key] = value |
| |
| return result |
| |
| if __name__ == "__main__": |
| assert merge_dictionaries({}, {}) == {} |
| assert merge_dictionaries({}, {"a": 23}) == {"a": 23} |
| assert merge_dictionaries({"a": 23}, {"b": 45}) == {"a": 23, "b": 45} |
| |
| e = None |
| try: |
| merge_dictionaries({"a": 23}, {"a": 45}) |
| except Exception as _e: |
| e = _e |
| assert isinstance(e, TypeError) |
| |
| assert merge_dictionaries({"a": 23}, {"a": 23}) == {"a": 23} |
| |
| assert merge_dictionaries({"a": {"b": 23}}, {"a": {"c": 45}}) == {"a": {"b": 23, "c": 45}} |
| assert merge_dictionaries({"a": {"b": 23}}, {"a": {"b": 23}}) == {"a": {"b": 23}} |
| |
| e = None |
| try: |
| merge_dictionaries({"a": {"b": 23}}, {"a": {"b": 45}}) |
| except Exception as _e: |
| e = _e |
| assert isinstance(e, TypeError) |
