config.ini

[FLAGS]

lr = 0.01
dropout = 0.2

[OTHER]

foo = hello
bar = 123.0

guild.yml

op:
  main: op --config config.ini
  flags-dest: config:config.ini
  flags-import:
    - FLAGS.lr
    - FLAGS.dropout
  flags:
    lr:
      arg-name: FLAGS.lr
    dropout:
      arg-name: FLAGS.dropout

op.py

import argparse
import configparser

p = argparse.ArgumentParser()
p.add_argument("--config")
args = p.parse_args()

cfg = configparser.ConfigParser()
cfg.read(args.config)

flags = cfg["FLAGS"]
for name, val in sorted(flags.items()):
    print("%s=%s" % (name, val))