Xarray time metadata

Time

When I try to use time attributes in the metadata template for my new data in xarray format, it often doesn’t work.

• I need to treat time separately as there are two ways to write the metadata of time: attribute or encoding.

first, copy the global attrs

ds.attrs = meta.attrs.copy()

second, copy the variable attrs manually

for v in vars = ["var1", "var2", "x", "y"]:
    if v in vars and v in meta:
        ds[v].attrs = meta[v].attrs.copy()

Now Time!

First, get all time attributes

time_attrs = ds['time'].attrs.copy()

Now, pull out ecoding components manually (unit, calendar)

time_unit = time_attrs.pop('units', 'days since 1970-01-01') # pop units from time_attrs or default
calendar = time_attrs.pop('calendar', 'standard') # pop calendar from time_attrs or default

Delete those variables from the dataset

for k in ['units', 'calendar']:
    ds['time'].attrs.pop(k, None) # add None otherwise error thrown

Now update dstime attribute with time_attrs

ds['time'].attrs.update(time_attrs)

Update dstime with encoding

ds['time'].encoding.update = (
    {
    units = time_units,
    calendar = time_calenar
})