How to use the salem.GeoNetcdf function in salem

with utils.ncDataset(ft) as nc:
        vt = nc.variables['time']
        assert vt[0] == 0
        assert vt[-1] == vt.shape[0] - 1
        t0 = vt.units.split(' since ')[1][:7]
        time_t = pd.date_range(start=t0, periods=vt.shape[0], freq='MS')
    with utils.ncDataset(fp) as nc:
        vt = nc.variables['time']
        assert vt[0] == 0.5
        assert vt[-1] == vt.shape[0] - .5
        t0 = vt.units.split(' since ')[1][:7]
        time_p = pd.date_range(start=t0, periods=vt.shape[0], freq='MS')

    # Now open with salem
    nc_ts_tmp = salem.GeoNetcdf(ft, time=time_t)
    nc_ts_pre = salem.GeoNetcdf(fp, time=time_p)

    # set temporal subset for the ts data (hydro years)
    # the reference time is given by precip, which is shorter
    sm = cfg.PARAMS['hydro_month_nh']
    em = sm - 1 if (sm > 1) else 12
    yrs = nc_ts_pre.time.year
    y0, y1 = yrs[0], yrs[-1]
    if cfg.PARAMS['baseline_y0'] != 0:
        y0 = cfg.PARAMS['baseline_y0']
    if cfg.PARAMS['baseline_y1'] != 0:
        y1 = cfg.PARAMS['baseline_y1']

    nc_ts_tmp.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))
    nc_ts_pre.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))

fp = utils.get_histalp_file('pre')
    with utils.ncDataset(ft) as nc:
        vt = nc.variables['time']
        assert vt[0] == 0
        assert vt[-1] == vt.shape[0] - 1
        t0 = vt.units.split(' since ')[1][:7]
        time_t = pd.date_range(start=t0, periods=vt.shape[0], freq='MS')
    with utils.ncDataset(fp) as nc:
        vt = nc.variables['time']
        assert vt[0] == 0.5
        assert vt[-1] == vt.shape[0] - .5
        t0 = vt.units.split(' since ')[1][:7]
        time_p = pd.date_range(start=t0, periods=vt.shape[0], freq='MS')

    # Now open with salem
    nc_ts_tmp = salem.GeoNetcdf(ft, time=time_t)
    nc_ts_pre = salem.GeoNetcdf(fp, time=time_p)

    # set temporal subset for the ts data (hydro years)
    # the reference time is given by precip, which is shorter
    sm = cfg.PARAMS['hydro_month_nh']
    em = sm - 1 if (sm > 1) else 12
    yrs = nc_ts_pre.time.year
    y0, y1 = yrs[0], yrs[-1]
    if cfg.PARAMS['baseline_y0'] != 0:
        y0 = cfg.PARAMS['baseline_y0']
    if cfg.PARAMS['baseline_y1'] != 0:
        y1 = cfg.PARAMS['baseline_y1']

    nc_ts_tmp.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))
    nc_ts_pre.set_period(t0='{}-{:02d}-01'.format(y0, sm),

if cfg.PATHS.get('climate_file', None):
        warnings.warn("You seem to have set a custom climate file for this "
                      "run, but are using the default CRU climate "
                      "file instead.")

    if cfg.PARAMS['baseline_climate'] != 'CRU':
        raise InvalidParamsError("cfg.PARAMS['baseline_climate'] should be "
                                 "set to CRU")

    # read the climatology
    clfile = utils.get_cru_cl_file()
    ncclim = salem.GeoNetcdf(clfile)
    # and the TS data
    nc_ts_tmp = salem.GeoNetcdf(utils.get_cru_file('tmp'), monthbegin=True)
    nc_ts_pre = salem.GeoNetcdf(utils.get_cru_file('pre'), monthbegin=True)

    # set temporal subset for the ts data (hydro years)
    sm = cfg.PARAMS['hydro_month_' + gdir.hemisphere]
    em = sm - 1 if (sm > 1) else 12
    yrs = nc_ts_pre.time.year
    y0, y1 = yrs[0], yrs[-1]
    if cfg.PARAMS['baseline_y0'] != 0:
        y0 = cfg.PARAMS['baseline_y0']
    if cfg.PARAMS['baseline_y1'] != 0:
        y1 = cfg.PARAMS['baseline_y1']

    nc_ts_tmp.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))
    nc_ts_pre.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))
    time = nc_ts_pre.time

----------
    gdir : GlacierDirectory
        the glacier directory
    sigma_temp : float
        the standard deviation of the random timeseries (set to 0 for constant
        ts)
    sigma_prcp : float
        the standard deviation of the random timeseries (set to 0 for constant
        ts)
    seed : int
        the RandomState seed
    """

    # read the climatology
    clfile = utils.get_cru_cl_file()
    ncclim = salem.GeoNetcdf(clfile)

    # set temporal subset for the ts data (hydro years)
    sm = cfg.PARAMS['hydro_month_' + gdir.hemisphere]
    em = sm - 1 if (sm > 1) else 12

    y0, y1 = 1901, 2018
    if cfg.PARAMS['baseline_y0'] != 0:
        y0 = cfg.PARAMS['baseline_y0']
    if cfg.PARAMS['baseline_y1'] != 0:
        y1 = cfg.PARAMS['baseline_y1']

    time = pd.date_range(start='{}-{:02d}-01'.format(y0, sm),
                         end='{}-{:02d}-01'.format(y1, em),
                         freq='MS')
    ny, r = divmod(len(time), 12)
    assert r == 0

"""

    if cfg.PATHS.get('climate_file', None):
        warnings.warn("You seem to have set a custom climate file for this "
                      "run, but are using the default CRU climate "
                      "file instead.")

    if cfg.PARAMS['baseline_climate'] != 'CRU':
        raise InvalidParamsError("cfg.PARAMS['baseline_climate'] should be "
                                 "set to CRU")

    # read the climatology
    clfile = utils.get_cru_cl_file()
    ncclim = salem.GeoNetcdf(clfile)
    # and the TS data
    nc_ts_tmp = salem.GeoNetcdf(utils.get_cru_file('tmp'), monthbegin=True)
    nc_ts_pre = salem.GeoNetcdf(utils.get_cru_file('pre'), monthbegin=True)

    # set temporal subset for the ts data (hydro years)
    sm = cfg.PARAMS['hydro_month_' + gdir.hemisphere]
    em = sm - 1 if (sm > 1) else 12
    yrs = nc_ts_pre.time.year
    y0, y1 = yrs[0], yrs[-1]
    if cfg.PARAMS['baseline_y0'] != 0:
        y0 = cfg.PARAMS['baseline_y0']
    if cfg.PARAMS['baseline_y1'] != 0:
        y1 = cfg.PARAMS['baseline_y1']

    nc_ts_tmp.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))
    nc_ts_pre.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))

gdir : :py:class:`oggm.GlacierDirectory`
        the glacier directory to process
    """

    if cfg.PATHS.get('climate_file', None):
        warnings.warn("You seem to have set a custom climate file for this "
                      "run, but are using the default CRU climate "
                      "file instead.")

    if cfg.PARAMS['baseline_climate'] != 'CRU':
        raise InvalidParamsError("cfg.PARAMS['baseline_climate'] should be "
                                 "set to CRU")

    # read the climatology
    clfile = utils.get_cru_cl_file()
    ncclim = salem.GeoNetcdf(clfile)
    # and the TS data
    nc_ts_tmp = salem.GeoNetcdf(utils.get_cru_file('tmp'), monthbegin=True)
    nc_ts_pre = salem.GeoNetcdf(utils.get_cru_file('pre'), monthbegin=True)

    # set temporal subset for the ts data (hydro years)
    sm = cfg.PARAMS['hydro_month_' + gdir.hemisphere]
    em = sm - 1 if (sm > 1) else 12
    yrs = nc_ts_pre.time.year
    y0, y1 = yrs[0], yrs[-1]
    if cfg.PARAMS['baseline_y0'] != 0:
        y0 = cfg.PARAMS['baseline_y0']
    if cfg.PARAMS['baseline_y1'] != 0:
        y1 = cfg.PARAMS['baseline_y1']

    nc_ts_tmp.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                         t1='{}-{:02d}-01'.format(y1, em))

"""

    if not (('climate_file' in cfg.PATHS) and
            os.path.exists(cfg.PATHS['climate_file'])):
        raise InvalidParamsError('Custom climate file not found')

    if cfg.PARAMS['baseline_climate'] not in ['', 'CUSTOM']:
        raise InvalidParamsError("When using custom climate data please set "
                                 "PARAMS['baseline_climate'] to an empty "
                                 "string or `CUSTOM`. Note also that you can "
                                 "now use the `process_histalp_data` task for "
                                 "automated HISTALP data processing.")

    # read the file
    fpath = cfg.PATHS['climate_file']
    nc_ts = salem.GeoNetcdf(fpath)

    # set temporal subset for the ts data (hydro years)
    sm = cfg.PARAMS['hydro_month_' + gdir.hemisphere]
    em = sm - 1 if (sm > 1) else 12
    yrs = nc_ts.time.year
    y0, y1 = yrs[0], yrs[-1]
    if cfg.PARAMS['baseline_y0'] != 0:
        y0 = cfg.PARAMS['baseline_y0']
    if cfg.PARAMS['baseline_y1'] != 0:
        y1 = cfg.PARAMS['baseline_y1']
    nc_ts.set_period(t0='{}-{:02d}-01'.format(y0, sm),
                     t1='{}-{:02d}-01'.format(y1, em))
    time = nc_ts.time
    ny, r = divmod(len(time), 12)
    if r != 0:
        raise InvalidParamsError('Climate data should be full years')