Cannot plot with windows paths syntax

[SamuelAnsel]

Bug Report

Windows path syntax

I work on windows and tried to display some plots, here is my dvc.yaml file :

  train:
    cmd: python .\src\train.py
    deps:
    - .\data\train.csv
    params:
    - train.batch_size
    - train.seed
    outs:
    - .\train_out
    metrics:
    - .\dvclive\metrics.json:
        cache: false
    plots:
    - .\dvclive\plots\metrics\train_loss.tsv:
        cache: false
        x: step
        y: train_loss
    - .\dvclive\plots\metrics\train_acc.tsv:
        cache: false
        x: step
        y: train_acc

Notice that my paths have a Windows syntax here.

If I run dvc plots show -v --json it outputs :

{
  ".\\dvclive\\plots\\metrics\\train_loss.tsv": [],
  ".\\dvclive\\plots\\metrics\\train_acc.tsv": []
}
2022-12-13 13:48:49,678 DEBUG: Analytics is enabled.
2022-12-13 13:48:49,681 DEBUG: Trying to spawn '['daemon', '-q', 'analytics', 'C:\\Users\\sansel\\AppData\\Local\\Temp\\tmpleidc5tk']'
2022-12-13 13:48:49,684 DEBUG: Spawned '['daemon', '-q', 'analytics', 'C:\\Users\\sansel\\AppData\\Local\\Temp\\tmpleidc5tk']'

Then if I replace \ with / in my paths like so :

stages:
  train:
    cmd: python ./src/train.py
    deps:
    - ./data/train.csv
    params:
    - train.batch_size
    - train.seed
    outs:
    - train_out
    metrics:
    - ./dvclive/metrics.json:
        cache: false
    plots:
    - ./dvclive/plots/metrics/train_loss.tsv:
        cache: false
        x: step
        y: train_loss
    - ./dvclive/plots/metrics/train_acc.tsv:
        cache: false
        x: step
        y: train_acc

Now DVC is able to correctly display plots.

Expected

You would expect Windows path syntax to work on Windows

Environment information

Output of dvc doctor:

$ dvc doctor

DVC version: 2.34.0 (exe)
---------------------------------
Platform: Python 3.10.8 on Windows-10-10.0.19044-SP0
Subprojects:

Supports:
        azure (adlfs = 2022.10.0, knack = 0.10.0, azure-identity = 1.12.0),
        gdrive (pydrive2 = 1.14.0),
        gs (gcsfs = 2022.11.0),
        hdfs (fsspec = 2022.11.0, pyarrow = 10.0.0),
        http (aiohttp = 3.8.3, aiohttp-retry = 2.8.3),
        https (aiohttp = 3.8.3, aiohttp-retry = 2.8.3),
        oss (ossfs = 2021.8.0),
        s3 (s3fs = 2022.11.0, boto3 = 1.24.59),
        ssh (sshfs = 2022.6.0),
        webdav (webdav4 = 0.9.8),
        webdavs (webdav4 = 0.9.8),
        webhdfs (fsspec = 2022.11.0)
Cache types: hardlink
Cache directory: NTFS on C:\
Caches: local
Remotes: None
Workspace directory: NTFS on C:\
Repo: dvc, git

You are using dvc version 2.34.0; however, version 2.37.0 is available.
To upgrade, uninstall dvc and reinstall from https://dvc.org.

[blakeNaccarato]

See my original comment where I provided a repro for a related issue. I have since renamed that repro to reflect its relationship to the current issue number 8689. Here's that repro again. It breaks a plot when there's a \ in the path. The plot path\fail.png doesn't show up in rendered HTML of dvc plots show, while path/pass.png does. The same goes for the plot rendering in the DVC VSCode extension. In fix-offending-plot the \ is swapped for /, then in remove-offending-plot the offending plot is commented out of dvc.yaml. Each branch has the output of dvc plots show committed as well.

It is not an exhaustive reproduction for this now broader issue, but represents one way in which Windows paths can mess things up.

Workaround

Here's an updated, generalized workaround since I last commented over in the other issue. Supply all paths in params.yaml under a key of your choosing (e.g. dirs), then inject them into dvc.yaml using DVC's built-in templating support (e.g. ${dirs.<...>}). Now you can watch your params.yaml for changes and always run a script like the repl_path_in_params.py below to normalize any \ to / before those parameters get injected into dvc.yaml. It's a bit of a bandaid solution, but it makes sure your paths are acceptable by DVC.

See below for an example normalizing script, parameters file, and dvc.yaml file.

repl_path_in_params.py

"""Replace Windows path separators with POSIX paths in configuration file."""

from pathlib import Path

from ruamel.yaml import YAML

PARAMS_FILE = "params.yaml"
DIRS_KEY = "dirs"

yaml = YAML()
yaml.indent(offset=2)


def main():
    params = yaml.load(PARAMS_FILE)
    params[DIRS_KEY] = repl_path(params[DIRS_KEY])
    yaml.dump(params, PARAMS_FILE)


def repl_path(dirs_dict: dict[str, Path]):
    """Replace Windows path separator with POSIX separator."""
    return {k: str(v).replace("\\", "/") for k, v in dirs_dict.items()}


if __name__ == "__main__":
    main()

params.yaml

dirs:
  plot_new_fit_0: data/metrics/plots/new_fit_0.png
  plot_new_fit_1: data/metrics/plots/new_fit_1.png
  plot_new_fit_2: data/metrics/plots/new_fit_2.png
  file_pipeline_metrics: data/metrics/tables/pipeline_metrics.json
other_params:
  ...

dvc.yaml

  ...
  metrics:
    cmd: "<metrics_cmd>"
    deps:
      - ...
    metrics:
      - "${dirs.file_pipeline_metrics}"
    plots:
      - "${dirs.plot_new_fit_0}"
      - "${dirs.plot_new_fit_1}"
      - "${dirs.plot_new_fit_2}"
    params:
      - ...
  ...

[daavoo]

Thanks for the workaround @blakeNaccarato 🙏
I will try to look into a proper fix when I find the time

[anitagraser]

The most tricky thing about this bug is that dvc stage add happily adds stages with backslashes in the path and dvc repro and dvc exp run run the stages without errors but then, suddenly, there are no plots.