解决ValueError: did not find a match in any of xarray‘s currently installed IO backends问题

利用cdsapi下载nc数据，后续利用xarray包拆分为单个逐日文件，一直报错：

ValueError: did not find a match in any of xarray's currently installed IO backends ['netcdf4', 'scipy']. Consider explicitly selecting one of the installed engines via the ``engine`` parameter, or installing additional IO dependencies, see:
https://docs.xarray.dev/en/stable/getting-started-guide/installing.html
https://docs.xarray.dev/en/stable/user-guide/io.html

确定文件夹权限设置无问题，写了个代码，测试我的文件是否是nc文件：

import netCDF4

try:
    with netCDF4.Dataset(r'C:\ERA\era-snowdepth\2018\2\snowdepth.nc') as nc:
        print('yes')
except Exception as e:
    print('no')

显示’no‘，开始反思下载nc数据的代码问题。
以下是我2024年12月16日下载nc文件的代码：

import cdsapi

c = cdsapi.Client()

c.retrieve(
    'reanalysis-era5-land',
    {
        'variable': [
            'snow_depth'
        ],
        'year': '2018',
        'month': '02',
        'day': [
            '01', '02', '03',
            '04', '05', '06',
            '07', '08', '09',
            '10', '11', '12',
            '13', '14', '15',
            '16', '17', '18',
            '19', '20', '21',
            '22', '23', '24',
            '25', '26', '27',
            '28'
        ],
        'time': '00:00',
        'area': [
            54, 73, 3,
            136,
        ],
        'data_format': 'netcdf',
    },
    'C:\\ERA\\era-snowdepth\\2018\\2\\snowdepth.nc')

我的文件夹也确实下载得到一个3408KB的.nc文件，但确实不是nc格式。

然后我去到CDS官网发现给出的官方代码有些许出入：

import cdsapi

dataset = "reanalysis-era5-land"
request = {
    "variable": ["snow_depth"],
    "year": "2018",
    "month": "02",
    "day": [
        "01", "02", "03",
        "04", "05", "06",
        "07", "08", "09",
        "10", "11", "12",
        "13", "14", "15",
        "16", "17", "18",
        "19", "20", "21",
        "22", "23", "24",
        "25", "26", "27",
        "28"
    ],
    "time": ["00:00"],
    "data_format": "netcdf",
    "download_format": "unarchived",
    "area": [54, 73, 3, 136]
}

client = cdsapi.Client()
client.retrieve(dataset, request).download()

运行之后测试是否是nc文件的代码输出yes，得到一个5204KB的nc文件

同时该文件可以顺利使用xarray分割，代码也放下面：

import xarray as xr

ds = xr.open_dataset(r"C:\ERA\era-snowdepth\2018\2\snowdepth.nc")
i = 0
while i<=27:
# 2018年的2月是28天
    f = ds['sde'][i,:,:]
    index = str(ds['sde'][i,:,:].valid_time.values)[:-19]
    f.to_netcdf(f'C:/ERA/era-snowdepth/2018/2/sde/{index}.nc')
    i=i+1

输出结果：