如果在absl-py中设置了另一个标志，如何将标志标记为必需的？

Question

我有两个标志f1和f2，f1是一个布尔标志。当f2被设置为True时，我希望将其标记为f1。absl-py有可能做到这一点吗？

Answer 1

您可以使用验证器：

from absl import app
from absl import flags

FLAGS = flags.FLAGS

flags.DEFINE_bool("f1", False, "some flag")
flags.DEFINE_string("f2", None, "some other flag")
flags.register_validator(
    # the flag to validate
    "f1",
    # a function that takes that flag's value and returns whether it's valid
    lambda value: not value or FLAGS.f2 is not None,
    # a message to print if it isn't
    message="if f1 is set, f2 needs to be set"
)

def main(argv):
    pass

if __name__ == '__main__':
    app.run(main)