Command format fix with backslashes on Windows System (#5280)

Fixes MONAI/apps/Auto3DSeg/bundle_gen.py

### Description

Commands ran in subprocess currently cause issues with string formatting
and backslashes not being escaped properly. Changing from Back Flash to
Forward Slash solves the issue.

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [ ] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [ ] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated, tested `make html` command in the `docs/`
folder.

Signed-off-by: Maxime <[email protected]>
Signed-off-by: Mingxin Zheng <[email protected]>
Signed-off-by: Mingxin Zheng <[email protected]>
Co-authored-by: Maxime <[email protected]>
Co-authored-by: Mingxin Zheng <[email protected]>
Co-authored-by: Mingxin Zheng <[email protected]>
Co-authored-by: Mingxin Zheng <[email protected]

Author: 4 people

monai/apps/auto3dseg/bundle_gen.py

@@ -15,6 +15,7 @@
 import subprocess
 import sys
 from copy import deepcopy
+from pathlib import Path
 from tempfile import TemporaryDirectory
 from typing import Any, Dict, List, Mapping
 
@@ -28,7 +29,7 @@
 from monai.utils import ensure_tuple
 
 logger = get_logger(module_name=__name__)
-ALGO_HASH = os.environ.get("MONAI_ALGO_HASH", "004a63c")
+ALGO_HASH = os.environ.get("MONAI_ALGO_HASH", "d7bf36c")
 
 __all__ = ["BundleAlgo", "BundleGen"]
 
@@ -152,7 +153,8 @@ def _create_cmd(self, train_params=None):
                     base_cmd += f"{train_py} run --config_file="
                 else:
                     base_cmd += ","  # Python Fire does not accept space
-                config_yaml = os.path.join(config_dir, file)
+                # Python Fire may be confused by single-quoted WindowsPath
+                config_yaml = Path(os.path.join(config_dir, file)).as_posix()
                 base_cmd += f"'{config_yaml}'"
 
         if "CUDA_VISIBLE_DEVICES" in params: