question: ModelCheckpoint creating unexpected subfolders
context: Hi! I have found a weird behavior when using ModelCheckpoint, if I have a metric that I want to save in my filename and it has a "/" on it it will create nested directories. For example
  checkpoint_callback = ModelCheckpoint(
          monitor='val/acc',
          dirpath=checkpoints_dir,
          filename='checkpoint_{epoch:02d}-{val/acc}',
          save_top_k=-1,
       )
  This one will create one extra folder per checkpoint:
  checkpoints/base_lstm/checkpoint_epoch=00-val/acc=0.04-v1.ckp
  checkpoints/base_lstm/checkpoint_epoch=00-val/acc=0.05-v1.ckp
  Is there any way to make the modelcheckpoint callback store the "val/acc" value while not using the string "val/acc" to reference it? Something like:
  checkpoints/base_lstm/checkpoint_epoch=00-valAcc=0.04-v1.ckp
  I think is quite standard to use "/" on tensorboard to be able to use the inbuilt tabs to better group metrics.
answer: hi, can you provide also your model sample, in particular, the metrics section
  I guess that the problem is with / as it is interpreted as a normal folder path, as you can see that 'val/acc' is not replaced by a number either... 🐰