回答如下：可以通过循环遍历字典中的键值对，判断值是否匹配，然后输出对应的键。示例代码如下：
```python
my_dict = {'a': 1, 'b': 2, 'c': 3}
def get_key_by_value(dict, value):
for k, v in dict.items():
if v == value:
return k
return None
value = 2
key = get_key_by_value(my_dict, value)
if key:
print(f'The key for value {value} is {key}')
else:
print(f'There is no key for value {value}')
```
输出结果为：`The key for value 2 is b`。
