Python将colorsys RGB坐标转换为十六进制

Question

根据这个答案，我在 Python 中生成了一些均匀分布的颜色，如下所示：

>>> import colorsys
>>> num_colors = 22
>>> hsv_tuples = [(x*1.0/num_colors, 0.5, 0.5) for x in range(num_colors)]
>>> rgb_tuples = map(lambda x: colorsys.hsv_to_rgb(*x), hsv_tuples)
>>> rgb_tuples
[(0.5, 0.25, 0.25), (0.5, 0.3181818181818182, 0.25), (0.5, 0.38636363636363635, 0.25), (0.5, 0.45454545454545453, 0.25), (0.4772727272727273, 0.5, 0.25), (0.4090909090909091, 0.5, 0.25), (0.34090909090909094, 0.5, 0.25), (0.2727272727272727, 0.5, 0.25), (0.25, 0.5, 0.2954545454545454), (0.25, 0.5, 0.36363636363636365), (0.25, 0.5, 0.43181818181818177), (0.25, 0.5, 0.5), (0.25, 0.4318181818181819, 0.5), (0.25, 0.36363636363636354, 0.5), (0.25, 0.2954545454545454, 0.5), (0.2727272727272727, 0.25, 0.5), (0.34090909090909083, 0.25, 0.5), (0.40909090909090917, 0.25, 0.5), (0.4772727272727273, 0.25, 0.5), (0.5, 0.25, 0.4545454545454546), (0.5, 0.25, 0.38636363636363646), (0.5, 0.25, 0.3181818181818181)]

现在如何从这些（“坐标？”）RGB 元组转换回 RGB 十六进制字符串，例如#FF00AA？可能是一个简单的问题，但我无法找到答案。

Answer 1

对于每种颜色，floor(color * 256)，以十六进制打印出来（填充到 2 位）。例如：

In [1]: rgb_tuples = [(0.5, 0.25, 0.25), (0.5, 0.3181818181818182, 0.25), (0.5, 0.38636363636363635, 0.25), (0.5, 0.45454545454545453, 0.25), (0.4772727272727273, 0.5, 0.25), (0.4090909090909091, 0.5, 0.25), (0.34090909090909094, 0.5, 0.25), (0.2727272727272727, 0.5, 0.25), (0.25, 0.5, 0.2954545454545454), (0.25, 0.5, 0.36363636363636365), (0.25, 0.5, 0.43181818181818177), (0.25, 0.5, 0.5), (0.25, 0.4318181818181819, 0.5), (0.25, 0.36363636363636354, 0.5), (0.25, 0.2954545454545454, 0.5), (0.2727272727272727, 0.25, 0.5), (0.34090909090909083, 0.25, 0.5), (0.40909090909090917, 0.25, 0.5), (0.4772727272727273, 0.25, 0.5), (0.5, 0.25, 0.4545454545454546), (0.5, 0.25, 0.38636363636363646), (0.5, 0.25, 0.3181818181818181)]

In [2]: for (r,g,b) in rgb_tuples:
   ...:     print '%02x%02x%02x' % (int(r*255), int(g*255), int(b*255))
   ...:     
804040
805140
806240
807440

Answer 2

1) 将浮点数乘以 256 并转换为整数。如果等于 256，则减 1。

编辑：由于我收到很多令人困惑的评论，因此必须乘以 256（如果最终为 256，则减去 1）的原因是为了获得与每个整数输出对应的完全相同数量的浮点值。

2）http://docs.python.org/2/library/string.html?highlight=hexadecimal#format-specation-mini-language

'x' 十六进制格式。输出以 16 为基数的数字，9 以上的数字使用小写字母。

使用它，将其设为大写并在其前面添加一个#。