1. 使用集合运算符 `-`
```python
set1 = {1, 2, 3, 4, 5}
set2 = {4, 5, 6, 7, 8}
set3 = set1 - set2
print(set3) 输出:{1, 2, 3}
2. 使用集合的方法 `difference`
```python
set1 = {1, 2, 3, 4, 5}
set2 = {4, 5, 6, 7, 8}
set3 = set1.difference(set2)
print(set3) 输出:{1, 2, 3}
3. 使用集合推导式
```python
set1 = {1, 2, 3, 4, 5}
set2 = {4, 5, 6, 7, 8}
set3 = {x for x in set1 if x not in set2}
print(set3) 输出:{1, 2, 3}
4. 使用 `symmetric_difference` 方法求对称差集,它返回在两个集合中的元素,但不在它们的交集中。
```python
set1 = {1, 2, 3, 4, 5}
set2 = {4, 5, 6, 7, 8}
set3 = set1.symmetric_difference(set2)
print(set3) 输出:{1, 2, 3, 6, 7, 8}