输入圆的半径R，调用自定义函数CircleArea()计算圆的面积并返回结果。(语言-python)

import math

① CircleArea(r):

area=math.pi*r*r

②   

R=float(input("请输入圆的半径R：")))

print("半径为{0}的圆面积为{1:.2f}".format(R, ③ ))

1、def
2、return area
3、CircleArea(R)

• 这篇博客: 【python教程】-- 入门 | 小甲鱼《零基础入门学Python》教程笔记（知识点详细、源码可复制）全中的 示例 - circle方法绘制圆形 部分也许能够解决你的问题, 你可以仔细阅读以下内容或跳转源博客中阅读:
  

• • circle方法绘制圆形
  • circle(Surface, color, pos, radius, width=0)

  • Surface参数：绘制在surface对象上
  • color参数：颜色
  • pos参数：圆心位置
  • radius参数：半径大小
  • width=0：边框大小。0表示填充矩形，1以上表示 使用color指定的颜色绘制边框

  # 跟随鼠标的圆形
  import pygame
  import sys
  from pygame.locals import *
  
  pygame.init()
  
  WHITE = (255, 255, 255)
  BLACK = (0, 0, 0)
  GREEN = (0, 255, 0)
  RED = (255, 0, 0)
  BLUE = (0, 0, 255)
  
  size = width, height = 640, 480
  screen = pygame.display.set_mode(size)
  pygame.display.set_caption("FishC Demo")
  
  position = size[0] // 2, size[1] // 2
  moving = False
  
  clock = pygame.time.Clock()
  
  while True:
      for event in pygame.event.get():
          if event.type == QUIT:
              sys.exit()
  
          if event.type == MOUSEBUTTONDOWN:
              if event.button == 1:
                  moving = True
  
          if event.type == MOUSEBUTTONUP:
              if event.button == 1:
                  moving = False
  
      if moving:
          position = pygame.mouse.get_pos()
  
      screen.fill(WHITE)
  
      pygame.draw.circle(screen, RED, position, 25, 1)
      pygame.draw.circle(screen, GREEN, position, 75, 1)
      pygame.draw.circle(screen, BLUE, position, 125, 1)
  
      pygame.display.flip()
  
      clock.tick(120)