编写一段Python代码，将给定的字符串中的所有单词都反转。


string = "Hello World, I am Belle."
```python
string = "Hello World, I am Belle."
reversed_string = ' '.join(word[::-1] for word in string.split())
print(reversed_string)
```

输出结果为 "olleH ,dlroW I ma elleB."