def _set_time_units_like(source_store: zarr.Group, target_store: zarr.Group):
"""Modify all time-like variables in source_store to use same units as
corresponding variable in target_store. The provided source_store must be
opened in a mode such that it can be modified (e.g. mode='r+')"""
for variable, source_array in source_store.items():
target_array = target_store[variable]
if "units" in source_array.attrs and "since" in source_array.attrs[
"units"]:
_set_array_time_units_like(source_array, target_array)
def _assert_chunks_match(source_group: zarr.Group, target_group: zarr.Group,
dim: str):
"""Ensure chunks for source and target groups are valid for appending.
Specifically:
1. all arrays in source_group have corresponding arrays in target_group.
2. chunk size is same for each array in source and target group.
3. dim length is a multiple of chunk size for target group.
In addition, log a warning if dim length is not a multiple of chunk size for source
group."""
for key, source_array in source_group.items():
if key not in target_group:
raise KeyError(
f"Cannot append {source_array} because there is no corresponding array "
f"in {target_group}.")
if dim != key and dim in source_array.attrs[XARRAY_DIM_NAMES_ATTR]:
axis = source_array.attrs[XARRAY_DIM_NAMES_ATTR].index(dim)
target_array = target_group[key]
_assert_array_chunks_match(source_array, target_array, axis)