netCDF4模块如何只读取指定时间段的数据？

Question

我想读取指定时间段内的 netCDF 数据。我尝试读取 ncfile 的名称是 file.nc 而 ncdump -c file.nc 的部分信息是

dimensions:
lat = 1 ;
lon = 1 ;
time = UNLIMITED ; // (744 currently)
variables:
float lat(lat) ;
    lat:units = "degrees_north" ;
    lat:long_name = "latitude" ;
float lon(lon) ;
    lon:units = "degrees_east" ;
    lon:long_name = "longitude" ;
double time(time) ;
    time:units = "hours since 2015-07-01 01:00:00" ;
    time:long_name = "time" ;
double rain(time, lat, lon) ;
    rain:_FillValue = -999000000. ;
    rain:units = "K" ;
    rain:standard_name = "temperature" 
data:

lat = 1 ;
lon = 1 ;
time = -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, ... 
737, 738, 739, 740, 741, 742 ;

这是我读取这个 ncfile 的脚本。

import netCDF4

nc = netCDF4.Dataset(file.nc, 'r')
data = nc.variables['temperature'][:] #I want to read between 2015-07-20 00:00 to 2015-07-24 23:00

我想在特定时间段之间读取并检测开始日期和结束日期。如何解决？

Answer 1

正如@Bart 所建议的，xarray 是正确的选择。这是答案 w/o xarray。 NetCDF4.date2index() 就是答案。

import netCDF4
import dateutil.parser

nc = netCDF4.Dataset(file.nc, 'r')

# all_times variable includes the time:units attribute
all_times = nci.variables['time']

sdt = dateutil.parser.parse("2015-07-20T00:00:00")
edt = dateutil.parser.parse("2015-07-24T23:00:00")

st_idx = netCDF4.date2index(sdt, all_times)
et_idx = netCDF4.date2index(edt, all_times)

data = nc.variables['temperature'][st_idx:et_idx+1,:] #I want to read between 2015-07-20 00:00 to 2015-07-24 23:00

netCDF4模块如何只读取指定时间段的数据？

How to read data only for a specified period with netCDF4 module?

python

netcdf

netcdf4