python求圆的面积：
from math import pi as PI
n = int(input())
area=PI*n*n
def mianji():
return(area）
print(round(area,2))
#输入6
输出：113.10
```
from math import pi as PI
n = int(input())
area=PI*n*n
print(f'{area:.2f}')
你写这个mianji函数干吗用啊？？？你想啥优化？
from math import pi as PI
n = int(input())
print(round(PI*n*n,2))
改成这样L：
from math import pi as PI
def mianji(n):
area=PI*n*n
return area
n = int(input())
print(round(mianji(n), 2))