可以使用count()方法来计算字符串中特定字符出现的次数。例如：
```python
string = "Hello, World!"
char = "l"
count = string.count(char)
print(f"The character '{char}' appears {count} times in the string.")
```
这将输出：
The character 'l' appears 3 times in the string.
