Newline problem of Monitor's ResultsWriter in Windows environments

https://github.com/DLR-RM/stable-baselines3/blob/e24147390d2ce3b39cafc954e079d693a1971330/stable_baselines3/common/monitor.py#L181 When running the codes in Windows environments, the logged csv files end each line with \r\r\n, making empty lines between data lines. From Python 3 documentation, adding newline='' as an argument of the open function seems able to solve the problem. https://docs.python.org/3/library/csv.html#examples

[Miffyli]

means something like self.file_handler = open(filename, “wt”, newline=“\n”) instead of using newline=“”.

What I meant is that all lines end with only a single “\n”, so this (the quoted part) might do the trick unless rest of the code adds additional “\n” or other characters into the mix 😃.

[araffin]

In such a case, I feel that MS Excel is more convenient, though this is just my experience.

I would disagree with that. Using tensorboard or simply python scripts/plot_train.py -a ppo -e Cartpole -f logs/ -w 100 from the RL Zoo are two convenient options. They also handle multi envs properly.