Returns the difference between two iterables.

Create a set from b, then use list comprehension on a to only keep values not contained in the previously created set, _b.

代码实现

def difference(a, b):
  _b = set(b)
  return [item for item in a if item not in _b]

使用样例

difference([1, 2, 3], [1, 2, 4]) # [3]