python-3.x - 警告模块两次打印部分警告

Question

如果我在脚本中使用这段代码:

import warnings
if True:
    warnings.warn(
        "The specified directory is not empty, and does not "
        "appear to contain a pipeline we can update. Exiting."
    )

我得到这个作为输出:

~ > create.py -p something -o .
somethings.py:58: UserWarning: The specified directory is not empty, and does not appear to contain a pipeline we can update. Exiting.
  "The specified directory is not empty, and does not"
~ >

为什么 The specified directory is not empty, and does not string printed again 我该如何关闭它？

最好的问候。

Answer 1

试试这个:

warnings.warn("The specified directory is not empty, and does not "
              "appear to contain a pipeline we can update. Exiting.", stacklevel=2)

这会给你以下警告:

sys:1: UserWarning: The specified directory is not empty, and does not appear to contain a pipeline we can update. Exiting.

警告默认为堆栈级别 1，这就是它被重复的原因。第一层堆栈告诉用户警告源自的确切代码行，这是您的警告函数调用行。所以通过将它放在堆栈级别 2，它不会显示警告行，而只会显示警告本身。

如果您有兴趣更多地自定义警告输出，可以使用 warnings.warn_explicit() 函数。

https://docs.python.org/3.6/library/warnings.html#available-functions