如何将此代码转换为f字符串？

Question

colors = ['black', 'white']
sizes = ['S', 'M', 'L']
for tshirt in ('%s %s' % (c, s) for c in colors for s in sizes):
    print(tshirt)

black S
black M
black L
white S
white M
white L

因此，我尝试删除那些％s％s，而是采用f字符串格式。有人可以表现出如何做到这一点吗？谢谢

Answer 1

>>> colors = ['black', 'white']
>>> sizes = ['S', 'M', 'L']
>>> for c in colors:
...    for s in sizes:
...        print(f'{c} {s}')

另一种方法是使用itertools.product：

>>> for c, s in itertools.product(colors, sizes):
...     print(f'{c} {s}')   

Answer 2

您可以将变量名写在花括号（{...}）中：

for tshirt in (f'{c} {s}' for c in colors for s in sizes):
    print(tshirt)

尽管在这种情况下使用生成器进行for循环有点奇怪：您可以将其展开成（两个）嵌套的for循环，例如@nosklo的回答（尽管这当然不会改变literal string interpolation [PEP-498]的用法。