LOOM_SPEC_VERSION

doc/format/index.rst

@@ -3,6 +3,12 @@
 Loom file format specs
 ======================
 
+Versions
+--------
+
+This specification defines the Loom file format version ``2.0.1``.
+
+
 .. _formatinfo:
 
 Introduction
@@ -89,6 +95,12 @@ Global attributes
    attribute <https://www.hdfgroup.org/HDF5/Tutor/crtatt.html>`__ on the
    root ``/`` group, which can be any valid scalar or multidimensional datatype and should be
    interpreted as attributes of the whole ``.loom`` file. 
+-  There can OPTIONALLY be an `HDF5
+   attribute <https://www.hdfgroup.org/HDF5/Tutor/crtatt.html>`__ on the
+   root ``/`` group named ``LOOM_SPEC_VERSION``, a string value giving the
+   loom file spec version that was followed in creating the file. See top of this
+   document for the current version of the spec.
+
 
 Row and column attributes
 ^^^^^^^^^^^^^^^^^^^^^^^^^

loompy/__init__.py

@@ -9,4 +9,5 @@
 from .to_html import to_html
 from .view_manager import ViewManager
 from .loompy import connect, create, create_append, combine, create_from_cellranger, LoomConnection
-from ._version import __version__
+from ._version import __version__, loom_spec_version
+

loompy/_version.py

@@ -1 +1,2 @@
 __version__ = '2.0.7'
+loom_spec_version = '2.0.1'

loompy/loompy.py

@@ -844,6 +844,8 @@ def create(filename: str, layers: Union[np.ndarray, Dict[str, np.ndarray], loomp
 	f.create_group('/layers')
 	f.create_group('/row_attrs')
 	f.create_group('/col_attrs')
+	f.create_group('/row_graphs')
+	f.create_group('/col_graphs')
 	f.flush()
 	f.close()
 
@@ -864,6 +866,7 @@ def create(filename: str, layers: Union[np.ndarray, Dict[str, np.ndarray], loomp
 			# store creation date
 			currentTime = time.localtime(time.time())
 			ds.attrs['CreationDate'] = timestamp()
+			ds.attrs["LOOM_SPEC_VERSION"] = loompy.loom_spec_version
 
 	except ValueError as ve:
 		ds.close(suppress_warning=True)