我有一个带有许多尺寸和属性的大型netcdf文件。我想从该文件中提取单个变量，并将其另存为新的netcdf文件，同时保留所有原始元数据。我正在使用xarray。
我使用以下方法打开数据集：
dr=xr.open_dataset("path_to_file")
[当我print时，它看起来像这样（为简单起见删除了一些尺寸和元数据：
<xarray.Dataset>
Dimensions: (Time: 464, bottom_top: 39, bottom_top_stag: 40, snow_layers_stag: 3, snso_layers_stag: 7, soil_layers_stag: 4, south_north: 186, south_north_stag: 187, west_east: 246, west_east_stag: 247)
Coordinates:
XLAT (Time, south_north, west_east) float32 ...
XLONG (Time, south_north, west_east) float32 ...
XTIME (Time) datetime64[ns] ...
XLAT_U (Time, south_north, west_east_stag) float32 ...
XLONG_U (Time, south_north, west_east_stag) float32 ...
XLAT_V (Time, south_north_stag, west_east) float32 ...
XLONG_V (Time, south_north_stag, west_east) float32 ...
Dimensions without coordinates: Time, bottom_top, bottom_top_stag, snow_layers_stag, snso_layers_stag, soil_layers_stag, south_north, south_north_stag, west_east, west_east_stag
Data variables:
Times (Time) |S19 ...
UST (Time, south_north, west_east) float32 ...
ZNU (Time, bottom_top) float32 ...
ZNW (Time, bottom_top_stag) float32 ...
ZS (Time, soil_layers_stag) float32 ...
DZS (Time, soil_layers_stag) float32 ...
Attributes:
TITLE: OUTPUT FROM WRF V3.9 MODEL
START_DATE: 2017-10-31_00:00:00
SIMULATION_START_DATE: 2017-10-01_00:00:00
WEST-EAST_GRID_DIMENSION: 247
SOUTH-NORTH_GRID_DIMENSION: 187
BOTTOM-TOP_GRID_DIMENSION: 40
HYBRID_OPT: -1
ETAC: 0.0
我只想提取UST，所以我尝试：
dr_u = dr['UST']
但是当我print结果dr_u时，元数据不见了：
<xarray.Dataset>
Dimensions: (Time: 464, south_north: 186, west_east: 246)
Coordinates:
XLAT (Time, south_north, west_east) float32 ...
XLONG (Time, south_north, west_east) float32 ...
XTIME (Time) datetime64[ns] ...
Dimensions without coordinates: Time, south_north, west_east
Data variables:
UST (Time, south_north, west_east) float32 ...
我希望能够将所有信息保留在原始文件中的Attributes标题下。我知道keep_attrs程序包中有一个名为xarray的标志，似乎对此很有用，但我无法弄清楚如何在此操作中使用它。
您可以使用ds.attrs从xarray对象中检索属性字典>
您可以手动分配属性：
dr_u.attrs = dr.attrs