check dest is group

Author: alimanfoo

zarr/convenience.py

@@ -636,6 +636,11 @@ def copy_store(source, dest, source_path='', dest_path='', excludes=None,
     return n_copied, n_skipped, n_bytes_copied
 
 
+def _check_dest_is_group(dest):
+    if not hasattr(dest, 'create_dataset'):
+        raise ValueError('dest must be a group, got {!r}'.format(dest))
+
+
 def copy(source, dest, name=None, shallow=False, without_attrs=False, log=None,
          if_exists='raise', dry_run=False, **create_kws):
     """Copy the `source` array or group into the `dest` group.
@@ -708,6 +713,9 @@ def copy(source, dest, name=None, shallow=False, without_attrs=False, log=None,
 
     """
 
+    # value checks
+    _check_dest_is_group(dest)
+
     # setup logging
     with _LogWriter(log) as log:
 
@@ -973,6 +981,9 @@ def copy_all(source, dest, shallow=False, without_attrs=False, log=None,
 
     """
 
+    # value checks
+    _check_dest_is_group(dest)
+
     # setup counting variables
     n_copied = n_skipped = n_bytes_copied = 0
 

zarr/tests/test_convenience.py

@@ -335,6 +335,14 @@ def test_copy_array(self):
         copy(source['spam'], dest)
         check_copied_array(source['spam'], dest['spam'])
 
+    def test_copy_bad_dest(self):
+        source = self.source
+
+        # try to copy to an array, dest must be a group
+        dest = self.new_dest().create_dataset('eggs', shape=(100,))
+        with pytest.raises(ValueError):
+            copy(source['foo/bar/baz'], dest)
+
     def test_copy_array_name(self):
         source = self.source
         dest = self.new_dest()