使用 python 在控制台中画圆

Question

我想在控制台中使用字符而不是像素画一个圆，为此我需要知道每一行有多少像素。直径作为输入给出，您需要输出一个列表，其中包含图片每行的宽度（以像素为单位）

例如：

输入：7

输出：[3, 5, 7, 7, 7, 5, 3]

输入：12

输出：[4, 8, 10, 10, 12, 12, 12, 12, 10, 10, 8, 4]

如何实施？

Answer 1

这很好地提醒了我在混合基于零和基于一的计算时要小心。在这种情况下，我不得不考虑 for 循环是从零开始的，但直径除以 2 的商是从一开始的。否则，地块将超过或低于 1。

顺便说一句，虽然我匹配了你对 7 的回答，但我没有为 12 想出完全相同的情节：

NOTE - Tested using Python 3.9.6

pixels_in_line = 0
pixels_per_line = []

diameter = int(input('Enter the diameter of the circle: '))

# You must account for the loops being zero-based, but the quotient of the diameter / 2 being
# one-based. If you use the exact radius, you will be short one column and one row.
offset_radius = (diameter / 2) - 0.5

for i in range(diameter):
    for j in range(diameter):
        x = i - offset_radius
        y = j - offset_radius
        if x * x + y * y <= offset_radius * offset_radius + 1:
            print('*', end='  ')
            pixels_in_line += 1
        else:
            print(' ', end='  ')
    pixels_per_line.append(pixels_in_line)
    pixels_in_line = 0
    print()

print('The pixels per line are {0}.'.format(pixels_per_line))

7 的输出：

Enter the diameter of the circle: 7
      *  *  *        
   *  *  *  *  *     
*  *  *  *  *  *  *  
*  *  *  *  *  *  *  
*  *  *  *  *  *  *  
   *  *  *  *  *     
      *  *  *        
The pixels per line are [3, 5, 7, 7, 7, 5, 3].

12 的输出：

Enter the diameter of the circle: 12
               *  *                 
         *  *  *  *  *  *           
      *  *  *  *  *  *  *  *        
   *  *  *  *  *  *  *  *  *  *     
   *  *  *  *  *  *  *  *  *  *     
*  *  *  *  *  *  *  *  *  *  *  *  
*  *  *  *  *  *  *  *  *  *  *  *  
   *  *  *  *  *  *  *  *  *  *     
   *  *  *  *  *  *  *  *  *  *     
      *  *  *  *  *  *  *  *        
         *  *  *  *  *  *           
               *  *                 
The pixels per line are [2, 6, 8, 10, 10, 12, 12, 10, 10, 8, 6, 2].

Answer 2

基于（所有功劳归功于 Rob！）我也设法调整了 12x12 像素网格的代码：

diameter = 12

radius = diameter / 2 - .5
r = (radius + .25)**2 + 1

result = ''

for i in range(diameter):
    y = (i - radius)**2
    for j in range(diameter):
        x = (j - radius)**2
        if x + y <= r:
            result = result + '*  '
        else:
            result = result + '   '
    result = result + '\n'

print(result)

result = result.split('\n')[:-1]
pixels_per_line = [x.count('*') for x in result]

print(f'The pixels per line are {pixels_per_line}.')

输出：

            *  *  *  *              
      *  *  *  *  *  *  *  *        
   *  *  *  *  *  *  *  *  *  *     
   *  *  *  *  *  *  *  *  *  *     
*  *  *  *  *  *  *  *  *  *  *  *  
*  *  *  *  *  *  *  *  *  *  *  *  
*  *  *  *  *  *  *  *  *  *  *  *  
*  *  *  *  *  *  *  *  *  *  *  *  
   *  *  *  *  *  *  *  *  *  *     
   *  *  *  *  *  *  *  *  *  *     
      *  *  *  *  *  *  *  *        
            *  *  *  *              

The pixels per line are [4, 8, 10, 10, 12, 12, 12, 12, 10, 10, 8, 4].

如果您需要圆圈内的空白区域，只需稍作改动即可：

diameter = 7

radius = diameter / 2 - .5
r = (radius + .25)**2 + 1
r_min = (radius - 1)**2 + 1 # <-------- here

result = ''

for i in range(diameter):
    y = (i - radius)**2
    for j in range(diameter):
        x = (j - radius)**2
        if r_min <= x + y <= r: # <----- here
            result = result + '*  '
        else:
            result = result + '   '
    result = result + '\n'

print(result)

输出：

      *  *  *        
   *  *     *  *     
*  *           *  *  
*                 *  
*  *           *  *  
   *  *     *  *     
      *  *  *

            *  *  *  *              
      *  *  *        *  *  *        
   *  *                    *  *     
   *                          *     
*  *                          *  *  
*                                *  
*                                *  
*  *                          *  *  
   *                          *     
   *  *                    *  *     
      *  *  *        *  *  *        
            *  *  *  *

使用 python 在控制台中画圆

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