## find_rule {#str}

The findRule method returns the rule with a key matching the passed key. If no such rule exists, a null value is returned


### Returns 


The found rule


```python
def find_rule(self, key):
    ...
```


| Parameter | Type | Description |
| :- | :- | :- |
| key | str | The key which described the rule to find. The key must resolve to a number between 0 and 1, or the rule is ignored. |



### See Also
* module [`aspose.svg.dom.css`](../../)
* class [`ICSSKeyframesRule`](/svg/python-net/aspose.svg.dom.css/icsskeyframesrule)