input: Write a python function to remove a key from a dictionary.
  assert remove_from_dict({'a': 1, 'b': 2, 'c': 3}, 'b') == {'a': 1, 'c': 3}
  assert remove_from_dict({'x': 10, 'y': 20, 'z': 30}, 'y') == {'x': 10, 'z': 30}
  assert remove_from_dict({'key1': 'value1', 'key2': 'value2'}, 'key1') == {'key2': 'value2'}
output: def remove_from_dict(d, key):
      if key in d:
          del d[key]
      return d