diff --git a/cfdm/read_write/netcdf/netcdfread.py b/cfdm/read_write/netcdf/netcdfread.py
index fe43e867c..bb1c8524e 100644
--- a/cfdm/read_write/netcdf/netcdfread.py
+++ b/cfdm/read_write/netcdf/netcdfread.py
@@ -1020,26 +1020,41 @@ def read(
# ------------------------------------------------------------
# Find the CF version for the file, and the CFA version.
+ # (See '2.6.1 Identification of Conventions' in the CF Conformance
+ # document for valid inputs for the 'Conventions' property.)
# ------------------------------------------------------------
Conventions = g["global_attributes"].get("Conventions", "")
-
# If the string contains any commas, it is assumed to be a
# comma-separated list.
- all_conventions = re.split(",\s*", Conventions)
+ all_conventions = re.split(r",\s*", Conventions)
if all_conventions[0] == Conventions:
all_conventions = Conventions.split()
file_version = None
for c in all_conventions:
- if c.startswith("CF-"):
- file_version = c.replace("CF-", "", 1)
- elif c.startswith("UGRID-"):
+ # Be particularly strict with the regex to account for ambiguous
+ # values e.g. CF-<badversionformat> or CF-1.X/CF-1.Y. Note that:
+ # * the '^' and '$' start and end of string tokens ensure that
+ # only zero or one match can be found per given string c;
+ # * the regex below ensures a valid input to
+ # Version(), allowing any level of versioning identifier
+ # detail e.g. 1.23.34.45.6 (for future-proofing).
+ # See https://packaging.python.org/en/latest/specifications/
+ # version-specifiers/ for more on valid input to Version()
+ v_id = r"^{}-(\d+(\.\d+)*)$"
+ cf_v = re.search(v_id.format("CF"), c)
+ u_v = re.search(v_id.format("UGRID"), c)
+ cfa_v = re.search(v_id.format("CFA"), c)
+
+ if cf_v:
+ file_version = cf_v.group(1)
+ elif u_v:
# Allow UGRID if it has been specified in Conventions,
# regardless of the version of CF.
- g["UGRID_version"] = Version(c.replace("UGRID-", "", 1))
- elif c.startswith("CFA-"):
+ g["UGRID_version"] = Version(u_v.group(1))
+ elif cfa_v:
g["cfa"] = True
- g["CFA_version"] = Version(c.replace("CFA-", "", 1))
+ g["CFA_version"] = Version(cfa_v.group(1))
elif c == "CFA":
g["cfa"] = True
g["CFA_version"] = Version("0.4")
@@ -1054,6 +1069,11 @@ def read(
file_version = self.implementation.get_cf_version()
g["file_version"] = Version(file_version)
+ if is_log_level_debug(logger):
+ logger.debug(
+ " Versioning:\n read_vars['file_version'] ="
+ f"{g['file_version']}"
+ ) # pragma: no cover
# Set minimum/maximum versions
for vn in ("1.6", "1.7", "1.8", "1.9", "1.10", "1.11"):
diff --git a/cfdm/read_write/read.py b/cfdm/read_write/read.py
index b96345878..2289be5eb 100644
--- a/cfdm/read_write/read.py
+++ b/cfdm/read_write/read.py
@@ -18,6 +18,7 @@ def read(
mask=True,
domain=False,
_implementation=_implementation,
+ _scan_only=False,
):
"""Read field or domain constructs from a dataset.
@@ -335,6 +336,7 @@ def read(
mask=mask,
domain=domain,
extra_read_vars=None,
+ _scan_only=_scan_only,
)
except MaskError:
# Some data required for field interpretation is missing,
diff --git a/cfdm/test/test_read_write.py b/cfdm/test/test_read_write.py
index 5e9c0ab8a..dc70e0e2d 100644
--- a/cfdm/test/test_read_write.py
+++ b/cfdm/test/test_read_write.py
@@ -702,6 +702,96 @@ def test_read_write_string(self):
):
self.assertTrue(i.equals(j, verbose=3))
+ def test_read_write_Conventions_version(self):
+ """Test processing of `Conventions` attribute to field property."""
+ from packaging.version import Version
+
+ f = cfdm.read(self.filename)[0]
+
+ # Construct single valid values for standards
+ valid_version_ends = ["1.11", "1", "2.30.4"]
+ cf_valid_conv = [f"CF-{v}" for v in valid_version_ends]
+ ugrid_valid_conv = [f"UGRID-{v}" for v in valid_version_ends]
+ cfa_valid_conv = [f"CFA-{v}" for v in valid_version_ends]
+ other_valid_conv = [f"somestandard-{v}" for v in valid_version_ends]
+
+ # Construct some mixed compound valid values for standards. Reverse
+ # one list to make version IDs differ on at least one standard.
+ zip_valid = list(zip(
+ cf_valid_conv, reversed(ugrid_valid_conv), cfa_valid_conv,
+ other_valid_conv
+ ))
+ # Only space and comma delimiters are valid (see Conformance doc.)
+ combinations_comma_delim = [",".join(c) for c in zip_valid]
+ combinations_space_delim = [" ".join(c) for c in zip_valid]
+
+ all_valid_conv = (
+ cf_valid_conv + ugrid_valid_conv + cfa_valid_conv +
+ other_valid_conv + combinations_comma_delim +
+ combinations_space_delim
+ )
+
+ # Check that valid Conventions version specifications get set as the
+ # corresponding version on the Conventions property.
+ for set_conv_value in all_valid_conv:
+ cfdm.write(f, tmpfile)
+
+ # Can't use cfdm to change Conventions property so must use netCDF4
+ # Open with append mode, just want to update the global attribute
+ n = netCDF4.Dataset(tmpfile, "a")
+ n.Conventions = set_conv_value
+ n.close()
+
+ g = cfdm.read(tmpfile)[0]
+ self.assertEqual(g.get_property("Conventions"), set_conv_value)
+
+ invalid_version_ends = ["1.1/1.2", "bad", ".11", ""]
+ cf_invalid_conv = [f"CF-{v}" for v in invalid_version_ends]
+ ugrid_invalid_conv = [f"UGRID-{v}" for v in invalid_version_ends]
+ cfa_invalid_conv = [f"CFA-{v}" for v in invalid_version_ends]
+ other_invalid_conv = [f"somestandard-{v}" for v in invalid_version_ends]
+ zip_invalid = zip(
+ cf_invalid_conv, ugrid_invalid_conv, cfa_invalid_conv,
+ other_invalid_conv
+ )
+ bad_combinations_good_delim = [",".join(c) for c in zip_invalid]
+ # Include valid values with bad (unsupported) delimiters
+ good_combinations_bad_delim = ["- ".join(c) for c in zip_valid]
+
+ all_invalid_conv = (
+ cf_invalid_conv + ugrid_invalid_conv + cfa_invalid_conv +
+ other_invalid_conv + bad_combinations_good_delim +
+ good_combinations_bad_delim
+ )
+
+ # Include a mixture of valid and invalid version specifiers
+ some_valid_some_invalid_conv = [
+ " ".join(c) for c in zip(
+ cf_invalid_conv, reversed(ugrid_valid_conv), cfa_invalid_conv,
+ other_valid_conv)
+ ]
+
+ # Check that invalid version specifications get ignored, so that the
+ # file is successfully read in, but is given default-logic version.
+ for set_conv_value in (
+ all_invalid_conv + some_valid_some_invalid_conv):
+ get_conv_value = f.get_property("Conventions")
+ cfdm.write(f, tmpfile)
+
+ # Can't use cfdm to change Conventions property so must use netCDF4
+ n = netCDF4.Dataset(tmpfile, "a")
+ n.Conventions = set_conv_value
+ n.close()
+
+ self.assertEqual(
+ cfdm.read(tmpfile, _scan_only=True)["file_version"],
+ Version(get_conv_value.lstrip("CF-"))
+ )
+ g = cfdm.read(tmpfile)[0]
+ # TODO: do we want to re-set the Conventions property as well,
+ # given it is invalid?
+ self.assertEqual(g.get_property("Conventions"), set_conv_value)
+
def test_read_write_Conventions(self):
"""Test the `Conventions` keyword argument to `write`."""
f = cfdm.read(self.filename)[0]