python - 'IndexError : tuple index out of range' whith str. 格式

Question

我做错了什么？

print('script executed in {time}{1:.2f} seconds'.format(time=elapsed_time))

我得到:

IndexError: tuple index out of range

预期输出:

script executed in 0.12 seconds

Answer 1

您创建了两个格式字段:

print('script executed in {time}{1:.2f} seconds'.format(time=elapsed_time))
#                         ^1    ^2

但只给str.format一个参数:

print('script executed in {time}{1:.2f} seconds'.format(time=elapsed_time))
#                                                       ^1

您需要使格式字段的数量与参数的数量相匹配:

print('script executed in {time:.2f} seconds'.format(time=elapsed_time))