Create the output directory if its missing and force is used, otherwise raise

conda_pack/cli.py

@@ -117,7 +117,8 @@ def build_parser():
                         help="Re-add excluded files matching this pattern")
     parser.add_argument("--force", "-f",
                         action="store_true",
-                        help="Overwrite any existing archive at the output path.")
+                        help=("Overwrite any existing archive at the output path, "
+                              "or create the output directory structure if it's missing."))
     parser.add_argument("--quiet", "-q",
                         action="store_true",
                         help="Do not report progress")

conda_pack/core.py

@@ -285,6 +285,18 @@ def _parcel_output(self, parcel_root, parcel_name, parcel_version, parcel_distro
         dest_prefix = os.path.join(parcel_root, arcroot)
         return dest_prefix, arcroot, triple
 
+    def _check_output_location(self, output, force):
+        if os.path.exists(output) and not force:
+            raise CondaPackException("File %r already exists" % output)
+
+        # `dirname` returns an empty string if the provided `output` is just a filename.
+        directory = os.path.dirname(output) or "."
+        if force:
+            os.makedirs(directory, exist_ok=True)
+
+        if not os.path.exists(directory):
+            raise CondaPackException(f"The target output directory {directory} does not exist")
+
     def pack(
         self,
         output=None,
@@ -340,8 +352,8 @@ def pack(
         verbose : bool, optional
             If True, progress is reported to stdout. Default is False.
         force : bool, optional
-            Whether to overwrite any existing archive at the output path.
-            Default is False.
+            Whether to overwrite any existing archive at the output path if present, or
+            create the output directory structure if it's missing. Default is False.
         compress_level : int, optional
             The compression level to use, from 0 to 9. Higher numbers decrease
             output file size at the expense of compression time. Ignored for
@@ -386,8 +398,7 @@ def pack(
             # Ensure the prefix is a relative path
             arcroot = arcroot.strip(os.path.sep) if arcroot else ""
 
-        if os.path.exists(output) and not force:
-            raise CondaPackException("File %r already exists" % output)
+        self._check_output_location(output, force)
 
         if verbose:
             print(f"Packing environment at {self.prefix!r} to {output!r}")
@@ -518,8 +529,8 @@ def pack(
     verbose : bool, optional
         If True, progress is reported to stdout. Default is False.
     force : bool, optional
-        Whether to overwrite any existing archive at the output path. Default
-        is False.
+        Whether to overwrite any existing archive at the output path if present, or
+        create the output directory structure if it's missing. Default is False.
     compress_level : int, optional
         The compression level to use, from 0 to 9. Higher numbers decrease
         output file size at the expense of compression time. Ignored for

conda_pack/tests/test_core.py

@@ -102,6 +102,31 @@ def test_ignore_errors_editable_packages():
     CondaEnv.from_prefix(py37_editable_path, ignore_editable_packages=True)
 
 
+def test_errors_when_target_directory_not_exists_and_not_force(tmpdir, py37_env):
+
+    target_directory = os.path.join(tmpdir, "not_a_real_directory/")
+    assert not os.path.exists(target_directory)
+
+    target_file = os.path.join(target_directory, "env.tar.gz")
+
+    with pytest.raises(CondaPackException) as exc:
+        py37_env.pack(output=target_file, force=False)
+
+    assert "not_a_real_directory" in str(exc.value)
+
+
+def test_creates_directories_if_missing_and_force(tmpdir, py37_env):
+
+    target_directory = os.path.join(tmpdir, "not_a_real_directory/")
+    assert not os.path.exists(target_directory)
+
+    target_file = os.path.join(target_directory, "env.tar.gz")
+
+    py37_env.pack(output=target_file, force=True)
+
+    assert os.path.exists(target_directory)
+
+
 def test_errors_pip_overwrites():
     with pytest.raises(CondaPackException) as exc:
         CondaEnv.from_prefix(py37_broken_path)

news/295-create-output-dir-if-missing-and-force

@@ -0,0 +1,21 @@
+### Enhancements
+
+* Creates the output directory if it does not already exist and `force` is used (#295)
+
+* Raise error before packing if the output directory is missing and `force` is not used (#295)
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>