FIX: Add unlink() with missing_ok for Python 3.7

Author: effigies

niworkflows/interfaces/bids.py

@@ -50,7 +50,7 @@
 from templateflow.api import templates as _get_template_list
 from ..utils.bids import _init_layout, relative_to_root
 from ..utils.images import set_consumables, unsafe_write_nifti_header_and_data
-from ..utils.misc import splitext as _splitext, _copy_any
+from ..utils.misc import splitext as _splitext, _copy_any, unlink
 
 regz = re.compile(r"\.gz$")
 _pybids_spec = loads(Path(_pkgres("niworkflows", "data/nipreps.json")).read_text())
@@ -669,7 +669,7 @@ def _run_interface(self, runtime):
                         new_header.set_data_dtype(data_dtype)
                 del nii
 
-            out_file.unlink(missing_ok=True)
+            unlink(out_file, missing_ok=True)
             if new_data is new_header is None:
                 _copy_any(orig_file, str(out_file))
             else:
@@ -710,11 +710,11 @@ def _run_interface(self, runtime):
                             legacy_metadata[key] = self._metadata.pop(key)
                     if legacy_metadata:
                         sidecar = out_file.parent / f"{_splitext(str(out_file))[0]}.json"
-                        sidecar.unlink(missing_ok=True)
+                        unlink(sidecar, missing_ok=True)
                         sidecar.write_text(dumps(legacy_metadata, sort_keys=True, indent=2))
                 # The future: the extension is the first . and everything after
                 sidecar = out_file.parent / f"{out_file.name.split('.', 1)[0]}.json"
-                sidecar.unlink(missing_ok=True)
+                unlink(sidecar, missing_ok=True)
                 sidecar.write_text(dumps(self._metadata, sort_keys=True, indent=2))
                 self._results["out_meta"] = str(sidecar)
         return runtime

niworkflows/utils/misc.py

@@ -21,6 +21,7 @@
 #     https://www.nipreps.org/community/licensing/
 #
 """Miscellaneous utilities."""
+import os
 
 
 __all__ = [
@@ -333,5 +334,15 @@ def check_valid_fs_license():
     return proc.returncode == 0 and "ERROR:" not in proc.stdout.decode()
 
 
+def unlink(pathlike, missing_ok=False):
+    """Backport of Path.unlink from Python 3.8+ with missing_ok keyword"""
+    # PY37 hack; drop when python_requires >= 3.8
+    try:
+        os.unlink(pathlike)
+    except FileNotFoundError:
+        if not missing_ok:
+            raise
+
+
 if __name__ == "__main__":
     pass